Effectiveness of interventions to reduce homelessness: a systematic review and meta‐analysis

This Campbell systematic review examines the effectiveness of interventions to reduce homelessness and increase residential stability for individuals who are homeless, or at risk of becoming homeless. Forty‐three studies were included in the review, 37 of which are from the USA. Included interventions perform better than the usual services at reducing homelessness or improving housing stability in all comparisons. These interventions are: High intensity case management Housing First Critical time intervention Abstinence‐contingent housing Non‐abstinence‐contingent housing with high intensity case management Housing vouchers Residential treatment These interventions seem to have similar beneficial effects, so it is unclear which of these is best with respect to reducing homelessness and increasing housing stability. Plain Language Summary Interventions to reduce homelessness and improve housing stability are effective There are large numbers of homeless people around the world. Interventions to address homelessness seem to be effective, though better quality evidence is required. What is this review about? There are large numbers of homeless people around the world. Recent estimates are over 500,000 people in the USA, 100,000 in Australia and 30,000 in Sweden. Efforts to combat homelessness have been made on national levels as well as at local government levels. This review assesses the effectiveness of interventions combining housing and case management as a means to reduce homelessness and increase residential stability for individuals who are homeless, or at risk of becoming homeless. What is the aim of this review? This Campbell systematic review examines the effectiveness of interventions to reduce homelessness and increase residential stability for individuals who are homeless, or at risk of becoming homeless. Forty‐three studies were included in the review, 37 of which are from the USA. What studies are included? Included studies were randomized controlled trials of interventions for individuals who were already, or at‐risk of becoming, homeless, and which measured impact on homelessness or housing stability with follow‐up of at least one year. A total of 43 studies were included. The majority of the studies (37) were conducted in the United States, with three from the United Kingdom and one each from Australia, Canada, and Denmark. What are the main findings of this review? Included interventions perform better than the usual services at reducing homelessness or improving housing stability in all comparisons. These interventions are: High intensity case management Housing First Critical time intervention Abstinence‐contingent housing Non‐abstinence‐contingent housing with high intensity case management Housing vouchers Residential treatment These interventions seem to have similar beneficial effects, so it is unclear which of these is best with respect to reducing homelessness and increasing housing stability. What do the findings of this review mean? A range of housing programs and case management interventions appear to reduce homelessness and improve housing stability, compared to usual services. However, there is uncertainty in this finding as most the studies have risk of bias due to poor reporting, lack of blinding, or poor randomization or allocation concealment of participants. In addition to the general need for better conducted and reported studies, there are specific gaps in the research with respect to: 1) disadvantaged youth; 2) abstinence‐contingent housing with case management or day treatment; 3) non‐abstinence contingent housing comparing group vs independent living; 4) Housing First compared to interventions other than usual services, and; 5) studies outside of the USA. How up‐to‐date is this review? The review authors searched for studies published up to January 2016. This Campbell systematic review was published in February 2018. Executive summary Background The United Nations Universal Declaration of Human Rights (Article 25) states that everyone has a right to housing. However, this right is far from being realized for many people worldwide. According to the United Nations High Commissioner for Refugees (UNHCR), there are approximately 100 million homeless people worldwide. The aim of this report is to contribute evidence to inform future decision making and practice for preventing and reducing homelessness. Objectives To identify, appraise and summarize the evidence on the effectiveness of housing programs and case management to improve housing stability and reduce homelessness among people who are homeless or at‐risk of becoming homeless. Search methods We conducted a systematic review in accordance with the Norwegian Knowledge Centre's handbook. We systematically searched for literature in relevant databases and conducted a grey literature search which was last updated in January 2016. Selection criteria Randomized controlled trials that included individuals who were already, or at‐risk of becoming, homeless were included if they examined the effectiveness of relevant interventions on homelessness or housing stability. There were no limitations regarding language, country or length of homelessness. Two reviewers screened 2,918 abstracts and titles for inclusion. They read potentially relevant references in full, and included relevant studies in the review. Data collection and analysis We pooled the results and conducted meta‐analyses when possible. Our certainty in the primary outcomes was assessed using the Grading of Recommendations Assessment, Development, and Evaluation for effectiveness approach (GRADE). Results We included 43 relevant studies (described in 78 publications) that examined the effectiveness of housing programs and/or case management services on homelessness and/or housing stability. The results are summarized below. Briefly, we found that the included interventions performed better than the usual services in all comparisons. However, certainty in the findings varied from very low to moderate. Most of the studies were assessed as having high risk of bias due to poor reporting, lack of blinding, or poor randomization and/or allocation concealment of participants. Case management Case management is a process where clients are assigned case managers who assess, plan and facilitate access to health and social services necessary for the client's recovery. The intensity of these services can vary. One specific model is Critical time intervention, which is based on the same principles, but offered in three three‐month periods that decrease in intensity. High intensity case management compared to usual services has generally more positive effects: It probably reduces the number of individuals who are homeless after 12‐18 months by almost half (RR=0.59, 95%CI=0.41 to 0.87)(moderate certainty evidence); It may increase the number of people living in stable housing after 12‐18 months and reduce the number of days an individual spends homeless (low certainty evidence), however; it may have no effect on the number of individuals who experience some homelessness during a two year period (low certainty evidence). When compared to low intensity case management, it may have little or no effect on time spent in stable housing (low certainty evidence). Critical time intervention compared to usual services may 1) have no effect on the number of people who experience homelessness, 2) lead to fewer days spent homeless, 3) lead to more days spent not homeless and, 4) reduce the amount of time it takes to move from shelter to independent housing (low certainty evidence). Abstinence‐contingent housing programs Abstinence‐contingent housing is housing provided with the expectation that residents will remain sober. The results showed that abstinence‐contingent housing may lead to fewer days spent homeless, compared with usual services (low certainty evidence). Non‐abstinence‐contingent housing programs Non‐abstinence‐contingent housing is housing provided with no expectations regarding sobriety of residents. Housing First is the name of one specific non‐abstinence‐contingent housing program. When compared to usual services Housing First probably reduces the number of days spent homeless (MD=‐62.5, 95%CI=‐86.86 to ‐38.14) and increases the number of days in stable housing (MD=110.1, 95%CI=93.05 to 127.15) (moderate certainty evidence). In addition, it may increase the number of people placed in permanent housing after 20 months (low certainty evidence). Non‐abstinence‐contingent housing programs (not specified as Housing First) in combination with high intensity case management may reduce homelessness, compared to usual services (low certainty evidence). Group living arrangements may be better than individual apartments at reducing homelessness (low certainty evidence). Housing vouchers with case management Housing vouchers is a housing allowance given to certain groups of people who qualify. The results showed that it mayreduce homelessness and improve housing stability, compared with usual services or case management (low certainty evidence). Residential treatment with case management Residential treatment is a type of housing offered to clients who also need treatment for mental illness or substance abuse. We found that it mayreduce homelessness and improve housing stability, compared with usual services (low certainty evidence). Authors’ conclusions We found that a range of housing programs and case management interventions appear to reduce homelessness and improve housing stability, compared to usual services. The findings showed no indication of housing programs or case management resulting in poorer outcomes for homeless or at‐risk individuals than usual services. Aside from a general need for better conducted and reported studies, there are specific gaps in the research. We identified research gaps concerning: 1)Disadvantaged youth; 2) Abstinence‐contingent housing with case management or day treatment; 3) Non‐abstinence contingent housing, specifically different living arrangements (group vs independent living); 4) Housing First compared to interventions other than usual services, and; 5) All interventions from contexts other than the USA.


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The Campbell Collaboration | www.campbellcollaboration.org What are the main findings of this review?
Included interventions perform better than the usual services at reducing homelessness or improving housing stability in all comparisons. These interventions are: These interventions seem to have similar beneficial effects, so it is unclear which of these is best with respect to reducing homelessness and increasing housing stability.

What do the findings of this review mean?
A range of housing programs and case management interventions appear to reduce homelessness and improve housing stability, compared to usual services.
However, there is uncertainty in this finding as most the studies have risk of bias due to poor reporting, lack of blinding, or poor randomization or allocation concealment of participants. In addition to the general need for better conducted and reported studies, there are specific gaps in the research with respect to: 1) disadvantaged youth; 2) abstinence-contingent housing with case management or day treatment; 3) non-abstinence contingent housing comparing group vs independent living; 4) Housing First compared to interventions other than usual services, and; 5) studies outside of the USA.

How up-to-date is this review?
The review authors searched for studies published up to January 2016. This Campbell systematic review was published in February 2018. 7 The Campbell Collaboration | www.campbellcollaboration.org

Executive summary Background
The United Nations Universal Declaration of Human Rights (Article 25) states that everyone has a right to housing. However, this right is far from being realized for many people worldwide. According to the United Nations High Commissioner for Refugees (UNHCR), there are approximately 100 million homeless people worldwide. The aim of this report is to contribute evidence to inform future decision making and practice for preventing and reducing homelessness.

Objectives
To identify, appraise and summarize the evidence on the effectiveness of housing programs and case management to improve housing stability and reduce homelessness among people who are homeless or at-risk of becoming homeless.

Search methods
We conducted a systematic review in accordance with the Norwegian Knowledge Centre's handbook. We systematically searched for literature in relevant databases and conducted a grey literature search which was last updated in January 2016.

Background Description of homelessness
The United Nations Universal Declaration of Human Rights (Article 25) states that everyone has a right to housing. However, this right is far from being realized for many people worldwide. According to the United Nations High Commissioner for Refugees (UNHCR), there are approximately 100 million homeless people worldwide (1).

Defining homelessness
The term "homeless" is defined differently according to context, purpose and the geographical setting. There are three basic domains for understanding "home" and "homelessness": 1) the physical domain (the absence of home); 2) the social domain (homelessness connected to discrimination and social exclusion), and 3) the legal domain (individuals have a right to tenancy, and people without homes still have rights and are deserving of dignity) (2,3).
In the European Union, four categories of homelessness have been developed: roofless, houseless, insecure housing and inadequate housing (3). In the United States, the Department of Housing and Urban Development defines a person as homeless "if he or she lives in an emergency shelter, transitional housing program (including safe havens), or a place not meant for human habitation, such as a car, abandoned building, or on the streets" (4). For the purpose of this review, the following Norwegian definition of homeless should be considered: "A person is homeless when s/he lacks a place to live, either rented or owned, and finds themselves in one of the three following situations: Has no place to stay for the night; Is referred to an emergency or temporary shelter/accommodation; Is a ward of the correctional and probation service and due to be released in two months at the latest; Is a resident of an institution and due to be discharged in two months at the latest; Lives with friends, acquaintances or family on a temporary basis" (5).
A glossary of terms related to homelessness, relevant interventions and study characteristics is included in Appendix 1. 12 The Campbell Collaboration | www.campbellcollaboration.org (1998) summarized the research on why case management has been widely implemented with homeless individuals (14): people who are homeless have multiple serious problems and their service needs are often unmet (15,16), and these services, and the necessary resources, are difficult to access (17). Furthermore, patients with a mental illness may refuse help and/or miss appointments and/or show aggressive or antisocial behaviour which leads to exclusion from care in many instances (16). Case managers are intended to help guide the individual through the system and facilitate their access to resources and services.
Morse (14) suggested that case management can be described in terms of seven process variables that impact on the intensity of care provided: 1. Duration of services (varying from brief or time limited to ongoing and open-ended) 2. Intensity of services (involving frequency of client contact, and client-staff ratios) 3. Focus of services (from narrow and targeted to comprehensive) 4. Resource responsibility (from system gatekeeper responsible for limiting service utilization to client advocate responsible for increasing access or utilization of services) 5. Availability (from scheduled office hours to 24-hour availability) 6. Location of services (from all services delivered in office to all delivered in vivo) 7. Staffing ratios and composition (from individual caseloads to interdisciplinary teams with shared caseloads) Case management interventions can be categorized into the following five models: broker case management (BCM), standard case management (SCM), intensive case management (ICM), assertive community treatment (ACT), and critical time intervention (CTI). See Table 3.1 in Appendix 3 for an adapted overview of case management models (14,18).
In this review, we have organized case management according to intensity: high versus low. The following is a description of the interventions included under high intensity case management: Assertive Community Treatment (ACT) is an example of intensive case management in which a high level of care is provided. The distinguishing features of ACT are described as follows: "case management provided by a multidisciplinary team of professionals, including psychiatrists, social workers, nurses, occupational therapists, vocational specialists, etc.; 24hour, 7 days a week coverage; assertive outreach; and providing support to clients in the community where they live rather than office-based practice" (19).
Intensive case management (ICM) is similar to ACT. However, the primary difference (McHugo et al., 2004;Meyer and Morrissey, 2007) is that while ACT involves a shared caseload approach, ICM case managers are responsible for their individual caseloads. Furthermore, each staff member of an ACT team provides direct services, while this is not the case when ICM is applied. Finally, ICM usually lacks a validated model including a manual for treatment fidelity. We will use the term intensive case management when referring to both categories (ICM and ACT). When it is necessary to separate the two alternatives, this is explicitly emphasized in the text.

How the interventions may work
There are two objectives of the interventions: first to get accommodation, and then to avoid eviction. Housing programs provide accommodation to individuals. Case management (low or high intensity) is intended to compensate for the clients' lack of resources and to help them either obtain accommodation, and/or after they have become housed, avoid eviction. It is a collaborative process, including assessment, planning, facilitation and advocacy for options and services.

Why it is important to do this review
Efforts to combat homelessness have been made on national levels as well as at local government level, including specific treatments for particular types of clients. In addition, there have been many evaluations of housing and treatment programs for homeless individuals and/or persons at risk of homelessness. Several reviews and meta-analyses have also been published (12,18,20,(28)(29)(30)(31)). Yet, a large share of the reviews are out of date, or do not focus on homelessness and residential stability as primary outcomes, or are not systematic reviews of effectiveness.
Tabol and colleagues (2010) (12) aimed to determine how clearly the supported/supportive housing model is described and the extent to which it is implemented correctly (treatment fidelity). Another recent systematic review by de Vet and colleagues focussed on case management for homeless persons. They identified 21 randomized controlled trials or quasi-experimental studies, but did not conduct a meta-analysis, or GRADE the certainty of the evidence. A review by Chilvers and colleagues published in 2006 looked specifically at supported housing for adults with serious mental illness, but did not identify any relevant studies (32). This review differs from previous attempts at reviewing the evidence in that we have only included randomized controlled trials that examine a broad range of interventions with follow-up of at least one year. Furthermore, we have pooled the results where possible which has allowed us to look at the evidence across studies and not conclude based on small sample sizes from individual studies. Finally, we have applied GRADE to the outcomes, thus providing a more concrete indication of our certainty in the evidence. 16 The Campbell Collaboration | www.campbellcollaboration.org

Objectives
The primary objective was to assess the effectiveness of various interventions combining housing and case management as a means to reduce homelessness and increase residential stability for individuals who are homeless, or at risk of becoming homeless. Interventions include: • Abstinence-contingent housing, non-abstinence contingent housing, housing vouchers and residential treatment • High intensity case management (intensive case management and assertive community treatment), and low (ordinary or brokered) case management • Housing programs combined with case management programs. 17 The Campbell Collaboration | www.campbellcollaboration.org

Methods
This systematic review of the effectiveness of interventions to reduce homelessness and increase residential stability for people who are homeless was conducted in accordance with the guidelines in the NOKC Handbook for Summarizing Evidence (33) and the Cochrane Handbook for Systematic Reviews of Interventions (22).
This review was carried out in two phases. The first phase began with a literature search in 2010. The project was taken over in 2014 by the current review team and two updates to the original search were conducted in addition to a search for grey literature. We reassessed studies included by the original review team for inclusion, and excluded those with a quasi-experimental design (see further details below). Due to problems with archiving, there is no documentation of reasons for exclusion for some of the studies excluded in the first phase of the project.
A protocol was approved and published by the review team in the Campbell Library in 2010 (92). The protocol was used as the basis for the development of a protocol by the current review team which was approved and published on the NOKC website in 2014 (34) . The updated searches (2014 and 2016) were based on the search specified in the Campbell approved protocol, and the inclusion criteria are similar, aside from study design. There are four main differences between the protocol published in Campbell Library and the protocol for the current review: Firstly, in this review protocol we only included RCTs. This decision was based on the number of RCTs identified, which seemed sufficient even after the original search. Secondly, we did not include data or analyses related to cost effectiveness as these outcomes were not prioritized by our commissioners. Thirdly, we did not exclude studies if they did not sufficiently report the results. The results from these studies were reported narratively. Finally, we applied the GRADE approach to all primary outcomes. In addition, we conducted a search for grey literature through Google and Google Scholar and reference lists of identified and included studies using terms related to homelessness and housing. This search for grey literature was conducted in English, Norwegian, Swedish and Danish.
A research librarian planned and executed all the searches. The complete search strategy is published as an appendix to this report (Appendix 2). The search was last updated in January 2016.

Inclusion criteria Study design:
Randomized controlled trials

Population:
People who are homeless or at risk of becoming homeless. A homeless person is defined as a person living in the streets without a shelter that could be classified as "living quarters" with no place of usual residence and who moves frequently between various types of accommodation (including dwellings, shelters, institutions for the homeless or other living quarters) which may include living in private dwellings but reporting "no usual/permanent address" on their census form.
A person at risk of becoming homeless is someone who will be released from a prison, an institution (e.g. for psychiatric or rehabilitative care), or another accommodation within two months, and does not have any housing arranged for them in the near future (35). A person at risk can also be a person who lives temporarily with relatives or friends, or a person with short-term subletting contracts who has applied to social services or another organization for assistance in solving their housing situation.
There were no population restrictions regarding mental illness, addiction problems, age, gender, ethnicity, race, national contexts, etc. However, distinct subgroups were separated in our analyses when there was sufficient information in included studies.

Article selection
Two reviewers independently read and assessed references (titles and abstracts) for inclusion according to pre-defined inclusion criteria (see above). When at least one review author considered the reference potentially relevant, the reference was ordered to be read in full-text. Two reviewers independently read and assessed each article in full-text for inclusion according to a pre-defined inclusion form. Where differences in opinion emerged, the reviewers discussed until consensus was achieved. A third reviewer was brought in in instances where agreement was not possible, to assist in the decision.

Critical appraisal
The included studies were assessed for methodological limitations using the Cochrane Risk of Bias (RoB) tool (37). Studies were assessed as having low, unclear or high risk of bias related to: (1) randomization sequencing, (2) allocation concealment, (3) blinding of personnel and participants, (4) blinding of assessors for subjective outcomes and (5) objective outcomes, (6) incomplete outcome data, (7) selective reporting and (8) any other potential risks of bias. One reviewer assessed each study and a second reviewer checked each assessment and made comments where there were disagreements. Results of the Risk of Bias assessments were discussed until consensus was reached. 21 The Campbell Collaboration | www.campbellcollaboration.org

Data extraction
One reviewer systematically extracted data from the included studies using a pre-designed data recording form. A second reviewer then checked the data extraction for all included studies. Any differences or comments were discussed until consensus was achieved.
The following core data were extracted from all included studies: • Title, authors, and other publication details • Study design and aim • Setting (place and time of recruitment/data collection) • Sample population characteristics (age, gender, ethnicity, mental health/substance use status, homelessness status, criminal activity) • Intervention characteristics (degree and type of housing support and degree/type of service support and/or therapy offered) • Methods of outcome measurement (clinical, self-report, physical specimens for substance use outcomes) • Primary outcomes related to number of days spent in stable housing or homeless • Secondary outcomes related to housing (satisfaction with housing, type of housing, etc.), addiction status, mental or physical health, criminal activity, and/or quality of life.
Many of the studies were reported in more than one publication. One publication was identified as the main publication (usually the one with results related to the primary outcomes), and we only extracted data from publications in addition to the identified main publication when they added more information regarding the methods or results on relevant outcomes. We excluded studies if they reanalysed already included data using different techniques.
Given the complexity of the interventions being investigated, we attempted to categorize the included interventions along four dimensions: (1) was housing provided to the participants as part of the intervention; (2) to what degree was the tenants' residence in the provided housing dependent on, for example, sobriety, treatment attendance, etc.; (3) if housing was provided, was it segregated from the larger community, or scattered around the city; and (4) if case management services were provided as part of the intervention, to what degree of intensity. We created categories of interventions based on the above dimensions: 1. Case management only 2. Abstinence-contingent housing 3. Non-abstinence-contingent housing 4. Housing vouchers 5. Residential treatment with case management Some of the interventions had multiple components (e.g. abstinence-contingent housing with case management). These interventions were categorized according to the main component (the component that the primary authors emphasized). They were also placed in separate analyses. We 22 The Campbell Collaboration | www.campbellcollaboration.org then organized the studies according to which comparison intervention was used (any of the above interventions, or usual services).
For each comparison, we evaluated the characteristics of the population. In those cases where they were considered sufficiently similar (specifically with respect to individuals versus families, mental illness, substance abuse problems, literally homeless versus at risk of homelessness), and had comparable outcomes, the results from the studies were pooled in a meta-analysis when possible.
In those cases where the populations of studies with the same comparisons were considered too different to analyse together we have not pooled the results.
We extracted dichotomous and continuous data for all outcomes where available. We also extracted raw data and, when such data were available, adjusted outcome data (adjusted comparison (effect) estimates and their standard errors or confidence intervals). When information related to outcome measurement (e.g. sample sizes, exact numbers where graphs were only published in the article) were missing in the publication, we contacted the corresponding author(s) via e-mail and requested the data.

Data synthesis
Results for the primary outcomes (number of days spent in stable housing or homeless) are presented for each comparison along with a GRADE assessment. Results for secondary outcomes (for longest follow-up time) for each comparison were not synthesized, but are presented in Appendix 4. For comparisons where more than two studies are included, we present the primary outcomes with the longest follow-up time. Results for secondary outcomes are described in Appendix 4.
We summarized and presented data narratively in the text and table for each comparison. We also conducted a meta-analysis with random effects model and presented the effect estimate, relative risk and the corresponding 95% confidence interval (CI) using risk ratio for dichotomous outcomes. For continuous outcomes we analysed the data using (standardized) mean difference ((S)MD) with the corresponding 95% CI. We used SMD when length of time was measured different between pooled studies (e.g. in days versus months, etc.). We conducted meta-analyses using RevMan 5, using a random-effects model and inverse-variance approach (38). This method allowed us to weight each study according to the degree of variation in the confidence in the effect estimate.
In cases where the means, number of participants and test statistics for t-test were reported, but not the standard deviations, and there was the opportunity to include results in a meta-analysis, we calculated standard deviations, assuming same standard deviation for each of the two groups (intervention and control). 23 The Campbell Collaboration | www.campbellcollaboration.org

Heterogeneity
We assessed statistical heterogeneity using I 2 . Where I 2 was less than 25% we considered the results to have low heterogeneity. Where I 2 was greater than 50% we considered the results to have high heterogeneity. Where this heterogeneity could be explained, we proceeded to pool results. However, if heterogeneity could not be explained, we did not pool the results and presented the results separately for each study.

Subgroup analysis
We did not plan or conduct moderator or subgroup analyses.

Dependent effect sizes
We did not include a comparison group more than once in an analysis. Where we were interested in an intervention and it was compared to two or more comparison interventions that were both considered to be within the realm of "usual services", we combined the two comparison arms into one comparison group and compared the means of the combined control groups to the intervention for a given outcome (39).
In one study we have combined two intervention arms that both employed slightly differing versions of an intervention (assertive community treatment) into one intervention group and compared that to the usual services comparison condition (40).

Primary outcomes
Outcomes related to housing and homelessness were reported using multiple measurements/scales/methods in some studies. These included number of days spent in stable housing or homeless, length of time to move from shelter to permanent housing (measured in days), number or percentage of participants who reported being homeless during a given period, or at a certain measurement point, and the change in number/proportion of days spent in various living conditions between baseline and follow-up points.

Secondary outcomes
We did not synthesize or report results for secondary outcomes. They are described in Appendix 4 as they are reported in the original primary publications.

GRADING of the evidence
We assessed the certainty of the synthesized evidence for each primary outcome using GRADE (Grading of Recommendations Assessment, Development, and Evaluation). GRADE is a method for assessing the certainty of the evidence in systematic reviews, or the strength of recommendations in guidelines. Evidence from randomized controlled trials start as high certainty evidence but may be downgraded depending on five criteria in GRADE that are used to determine the certainty of the evidence: i) methodological study quality as assessed by review authors, ii)

Results
The search was conducted in three stages. The original systematic search of databases in 2010 resulted in 1,764 unique references ( Figure 1). We identified a further 831 unique references from the update search in 2014, and 323 more in the January 2016 update search. Altogether we identified 2,918 potentially relevant references through database searches. In addition, a grey literature search identified an additional 2 relevant studies (and 11 references). We excluded 2,526 references based on title and abstract. We read 394 references in full and excluded 316 based on the predefined inclusion and exclusion criteria. In total, we critically appraised 43 studies that were described in 78 publications. A list of excluded studies with reasons for exclusion is included in Appendix 5. Problems related to archiving from the first search in 2010 resulted in missing the references and the reasons for exclusion for 50 excluded studies.

Description of the included studies
We identified 43 randomized controlled studies (RCTs) reported in 78 publications (24, 26, 27, 39, 40, 42-81) that met our inclusion criteria, and two studies in progress (31, 82). See Appendix 9 for a description of the studies in progress.
Thirteen of the included studies were published in or after 2010, thirteen were published between 2000 and 2009, and seventeen studies were published before 2000.
The majority of the studies were conducted in the United States (n=37), and other included studies came from other high-income countries, including United Kingdom (n=3), Australia (n=1), Canada (n=1), and Denmark (n=1). Eleven of the studies were conducted at multiple sites (cities/institutions).
The duration of the intervention was not reported in all of the included studies. It appears that in most of these cases the intervention was available/offered until the longest follow-up. There were also some discrepancies between the number of participants randomized and the number of participants included in analyses in some cases. We have highlighted where we think this is a concern.
From these 43 RCTs we have summarized findings from 28 comparisons in five categories of interventions (see Table 1).

Risk of bias in the included studies
The majority of the RCTs were assessed as having high risk of bias. In many instances this was due to inadequate reporting of methods in general (unclear risk of bias). In particular, most studies were at unclear or high risk of selection bias because they either did not report randomization or allocation concealment procedures or reported inadequate methods of randomization or allocation concealment. The vast majority of studies were assessed as having unclear or high risk of performance bias: Blinding of participants and personnel was either not described in many studies (unclear risk), or not possible and reported as such (high risk). In the majority of studies outcome assessors were not blinded (high risk), or blinding was not mentioned (unclear risk). The risk of bias was separated into blinding of outcome assessment for subjective and objective outcomes due to the poor reporting, or lack, of blinding. The intention behind this was to indier4';cate that the blinding might have an impact on subjective outcomes, but not objective outcomes such as death or number of days housed when the data came from administrative records. Some studies also were assessed as being at high risk for attrition bias because they used inappropriate methods for dealing with missing data, or reporting bias because the results were not reported for all outcomes. It is not clear how much attrition has occurred in many of the primary studies, and in some cases the level of attrition differs between results within the same study but is not discussed by the primary authors. See Appendix 6 for a more detailed explanation of the risk of bias assessment for each study. 28 The Campbell Collaboration | www.campbellcollaboration.org

Interventions and comparisons
We included and extracted data from 43 RCTs (this information was presented in 78 publications). Some studies included multiple comparisons (multiple interventions), and some publications reported results from multiple studies (for example information related to two studies in one publication). Details on all of the included comparisons are described below. Details regarding data related to secondary outcomes is not reported in the main text of this report but can be found in Appendix 4.
The case management component in the included studies varied in terms of approach, intensity and case-load for case managers. We have therefore categorized case management components as either low intensity (case management with no further details, brokered case management), high intensity (Assertive Community Treatment or Intensive Case Management), or Critical Time Intervention (intensive case management for a shorter defined period of time). In addition, some interventions included a housing component and a treatment component that could not be described as case management (e.g. day treatment or Community Reinforcement Approach). Interventions including these treatment components have been analysed separately from interventions that include low or high intensity case management components. Most of the interventions evaluated in the included comparisons were complex in that they were made up of multiple components, and there was a large degree of flexibility in terms of how the interventions were implemented (including varying levels of treatment fidelity). Furthermore, many of the studies reported that the interventions and control conditions changed and evolved during the course of the studies in terms of organization, and availability of resources and services. More details on the interventions evaluated in each study is reported under the relevant comparison.
The comparison groups varied considerably, and in many cases it is difficult to ascertain what kind of interventions participants in these groups received/were offered due to poor reporting. The comparison groups were described as usual services (care as usual), other types of housing programs or case management interventions, or other types of interventions. All of the comparison 30 The Campbell Collaboration | www.campbellcollaboration.org  Table 3 presents an overview of the populations, interventions, comparisons and outcomes in the included studies. The total number of participants indicates the number of participants randomized. The number of participants for each group does not always add up to the total number of participants because most studies reported the number included in analyses, but not always the number randomized. Participants in the included studies were adults (>18 years old) unless otherwise specified. We report the longest outcome assessment for each study (shorter follow-up assessments were also done in some studies).

Description of the intervention
The case management intervention in the included studies varied considerably in terms of intensity, organization and length. The interventions are described in more detail under the relevant comparison and in Appendix 7.

Category 1.A: High intensity case management
We identified 18 studies that evaluated the effect of high intensity case management on housing stability and/or homelessness (39, 40, 44-46, 48, 50, 52-54, 59, 60, 69-71, 76, 80, 83). High intensity case management included interventions which were described as using either Assertive Community Treatment (ACT; N=12) or intensive case management (ICM; N=6). The included interventions varied in terms of ratio of clients per case manager, frequency of contact, length of treatment and follow-up, location of appointments, degree of service provision versus referral, and team versus individual approach to case management.
The interventions in the majority of the included studies (N=13) are compared to usual services (44-46, 48, 50, 54, 59, 60, 69-71, 80, 83). One study compared the intervention to another type of high intensity case management (76) and two studies compared it to low intensity case management (53, 69). In two of the included studies, multiple intervention arms or comparison arms were relevant for this category of interventions (39, 40). In one study we have combined two intervention arms that both employed slightly differing versions of assertive community treatment into one intervention group compared to usual services (40). In the other study (39), we combined two comparison arms that both offered usual services to participants into one comparison group compared to the intervention.
Services provided as part of "usual services" varied greatly between and within the studies. We have chosen to include all studies that compared high intensity case management to "usual services" in one comparison. The term "usual services" covers a wide variety of services, but generally refers to the variety of services available to any person meeting the eligibility criteria of the study and not an alternative intervention which participants who are not randomized to the intervention group receive. Usual services in the included studies included drop-in centres, provision of a list of services and information (69), case management style services (59) and 34 The Campbell Collaboration | www.campbellcollaboration.org limited peer coaching (83). Control conditions were too poorly described in most studies to accurately document what participants had access to.

1.A.1. High intensity case management compared to usual services
We identified 18 studies (39, 40, 44-46, 48, 50, 52-54, 59, 60, 69-71, 76, 80, 83) which evaluated the effect of high intensity case management compared to usual services on housing stability and homelessness in the USA (N=15), United Kingdom (N=2) and Denmark (N=1). The included studies were conducted over a long span of time; however, the majority of studies were conducted or began before the end of 2000 (N=12).
Fifteen of the included studies focused on adults with mental illness and/or substance abuse issues (39, 40, 44, 45, 48, 50, 52-54, 59, 60, 69-71, 76). One study focused on disadvantaged youth (46), one study included adults with families (80), and one study targeted recently released criminal offenders (83). While the studies differed slightly in the populations targeted, all of the studies included participants with mental illness and/or substance abuse even when that was not the main identifying characteristic of the target population. Information regarding mental illness and substance abuse was not reported for the study on disadvantaged youth; however, there was little reason to assume that this group would react differently to the intervention. More importantly, given the outcomes analysed here, housing stability and homelessness, one can assume that this is a universally sought after outcome, and the characteristics of the population might not be considered to be important. Below is a description of the results.
We carried out a meta-analysis for number of days in stable housing, pooling available data from four included studies (46, 50, 60, 69, 71) to examine the effect of high intensity case management compared to usual services on number of days in stable housing. As evident from the forest plot ( Figure 2), the pooled analysis indicates that the high intensity case management leads to an increase in the number of days spent in stable housing compared to usual services (SMD=0.90, 95% CI=0.00 to 1.79). Although considerable heterogeneity is indicated by I 2 and Chi 2 (I 2 =98%, chi 2 =186.17), this is expected due to the complexity of the included interventions, the geographical range of included studies (multiple cities across USA, and Australia) and the wide range of when the interventions were implemented. 35 The Campbell Collaboration | www.campbellcollaboration.org We carried out a meta-analysis to estimate the number of participants in stable housing at 12-18 months after the start of the intervention, pooling available data from two included studies (45, 54). As evident from the forest plot (Figure 3), the pooled analysis indicates that high intensity case management leads to a greater number of individuals living in stable housing compared to usual services (RR=1.26, 95% CI= 1.07 to 1.49). While the heterogeneity was assessed as being high (I 2 =73%, chi 2 =3.64), this can be accounted for by differences in when the interventions were implemented (approximately 15 years between publications) and assessed and geographical differences (UK and USA). Together these differences may have implications for political or social contexts which may, in turn, have impacted, for example, the type of usual services being provided.

Figure 3: Number of participants in stable housing, 12-18 months follow-up, high intensity case management vs usual services
It is uncertain whether high intensity case management improves either the length of time individuals spend in their longest recorded residence, the number of clients who do not move (45), or the number of moves during the last half of a one or two year period (45).
One study reported that there was no difference between the intervention and control groups in the number of moves reported during the previous 12 months as measured at 24 months MD=0.30 (-0.04, 0.64) (46). We carried out a meta-analysis for the number of days spent homeless, pooling available (adjusted) data from six included studies (39, 46, 50, 60, 71, 80). One of the studies adjusted the results for demographic characteristics, specifically ethnicity (60). This study (60) also reported both number of days homeless in shelter and number of days homeless on streets. It was not possible to combine the data from these two outcomes (means and the standard error of the mean (SEM) were reported, but not the number of participants who reported experiencing these living arrangements), so we have chosen to include the number of days homeless in shelter in this metaanalysis. The pooled estimate indicates that high intensity case management leads to fewer days spent homeless compared to usual services. Although there is considerable heterogeneity (I 2 =58%, chi 2 =11.77), this may be explained by a wide range of geographical settings (USA and Australia), and large differences in when the interventions were implemented and assessed (from 1990s to 2006). Together these differences may have implications for political or social contexts which may, in turn, have impacted, for example, the type of usual services being provided.

Figure 4: Number of days homeless, 12-24 months, high intensity case management vs usual services
In one study (44), high intensity case management seemed to lead to fewer months homeless (mean number of months per 100 months homeless). However, the 95% confidence interval indicates that high intensity case management might make little or no difference the amount of time spent homeless (results as reported in original publication: n=-1.5 [95% CI -4.3 to 1.3], p=0.29).
One study reported that participants in the high intensity case management group reported spending almost half as many days living on the street than participants in the usual services group (MD=0-14.10 (-15.77, -12.43)) (60) Three studies reported whether participants experienced homelessness during the study period (44, 48, 83). We conducted a meta-analysis for the number of participants who experienced at least one episode of homelessness within one to two years, pooling data from two studies (48, 83). The third study was not included in the analysis due to incomplete reporting of results (baseline and follow-up percentage of participants was not reported, only the pre-post difference in percentage of participants who experienced homelessness during a two year period was reported along with the difference in difference (44).
The pooled analysis, shown in Figure 5, indicates that high intensity case management may lead to little or no difference in whether individuals experience homelessness during a one to two year 37 The Campbell Collaboration | www.campbellcollaboration.org period compared to usual services. Results, as reported in the original publication, from the third study support this (Bell 2015 (44): OR=0.83, 95% CI=0.60 to 1.17).

Figure 5: Number of participants who experienced at least one episode of homelessness, 12-24 months, high intensity case management vs usual services
Three studies examined the number of participants who reported being homeless at the last followup point (12 to 18 months after baseline) (54, 59, 70). We conducted a meta-analysis for the number of participants who were homeless 12 to 18 months after the beginning of the study, pooling available data from three studies (54, 59, 70). One study reported the percentage of participants per group, but not the total number per group (amount of data on participants varied according to outcome), so we calculated the total number of participants per group using the information provided (70). As evident from the forest plot ( Figure 6), the pooled analysis indicates that high intensity case management probably leads to fewer individuals who report being homeless at the 12 to 18 month follow-up interview compared to usual services (RR=0.59, 95% CI=0.41 to 0.87). The results and quality assessments for high intensity case management compared to usual services on housing stability and homelessness for adults with mental illness and/or substance abuse problems are summarized in Table 4. The complete GRADE evidence profile is shown in Appendix 8,  ⨁◯◯◯ VERY LOW 10,11 *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; SMD: Standardised mean difference; RR: Risk ratio; MD: Mean difference 1.
Risk of performance bias in all studies. Risk of attrition bias in three studies, risk of detection bias in two studies and risk of selection bias in one study. Inadequate reporting of randomization and/or allocation concealment methods in two studies and blinding of outcome assessors in one study.

3.
Risk of performance bias.

5.
Risk of performance bias in all studies. Risk of attrition bias in one study. 6.
Risk of performance bias in four studies, risk of detection bias in two studies, risk of attrition bias in two studies and other risks of bias in two studies. Unclear reporting of selection bias in four studies and detection bias in two studies.
Inadequate reporting of randomization, allocation concealment and blinding methods in two studies.
Total number of events is less than 300. 10. Risk of detection bias and attrition bias. Inadequate reporting of blinding methods for participants and personnel. 11. Fewer than 400 participants. 12. Two studies included in the pooled analysis (Garety 2006 (54), Killaspy 2006). Nordentoft 2010 (N=496) showed that the intervention led to fewer homeless participants at 12 month follow-up than the control group (OR=0.53, 95%CI=0.3, 0.9). 13. Risk of performance bias in four studies, risk of detection bias in two studies, risk of attrition bias in two studies and other risks of bias in two studies.
Unclear reporting of selection bias in four studies and detection bias in two studies.
What does the evidence say? High intensity case management compared to usual services: • Probably reduces the number of individuals who are homeless after 12-18 months (moderate certainty evidence). • May increase the number of the number of people living in stable housing after 12-18 months (low certainty evidence). • May lead to little or no difference in the number of individuals who experience some homelessness during a two year period (low certainty evidence). • May reduce the number of days an individual spends homeless (low certainty evidence).
• It is uncertain whether high intensity case management leads to a difference in the number of days an individual spends in stable housing, the number of days an individual spends in their longest residence, and the number of individuals who do or do not move (very low certainty evidence).

1.A.2. High intensity case management compared to low intensity case management
We identified three studies (40, 52, 53) that examined the effects of integrated high intensity case management compared to standard case management (lower intensity) on housing stability and homelessness. The integrated treatment was based on the assertive community treatment model of case management in all three studies. Integrated treatment differs from standard case management models in that it integrates treatment for substance abuse and mental health issues into one service.
In one study (40), participants were randomized to either assertive community treatment, assertive community treatment with a community worker or brokered case management. The primary authors' most central hypothesis was that assertive community treatment was better for clients with serious mental health issues than brokered case management. This focus fits with the aim of our review and we therefore attempted to combine results from the two assertive community treatment groups to compare them to the brokered case management group (usual services). For the purpose of this review we are interested only in the assertive community treatment condition and have thus combined the two interventions which employed the assertive community treatment model of case management. In this study the assertive community treatment model was expanded and modified: staff were instructed to visit shelters and were trained in engaging with homeless persons.
In two studies (52, 53), the high intensity case management interventions were based on the assertive community treatment model and were provided by two sites (health centres).  The results and quality assessments for high intensity case management compared to low intensity case management are summarized in Table 5. The complete GRADE evidence profile is shown in Appendix 8,  Risk of detection bias in one study. Inadequate reporting of methods in both studies.

2.
The third study that could not be included in the pooled analysis (Morse 1997 While only two studies are included in the analysis reported here (total population of 401 participants), the outcome is examined in three studies (total population of 458 participants).

What does the evidence say?
High intensity case management compared with low intensity case management for individuals with mental illness and substance abuse problems: • May lead to little or no difference in the number of days people spend in stable housing (low certainty evidence).

1.A.3. High intensity case management compared to other intervention (no case management or housing program)
The study (83) that examined the effect of high intensity case management compared to another intervention that did not include case management or housing on housing stability and homelessness included three trial arms. The first comparison (high intensity case management compared to usual services) is included above. The high intensity case management intervention is described above, and the comparison condition consisted of peer coaching with brief nurse counselling which was identical to the peer coaching component of the intervention program, but lacked the case management component. The results and quality assessments for high intensity case management compared to another intervention with no housing or case management component for recently released criminal offenders are summarized in Table 6. The complete GRADE evidence profile is shown in Appendix 8,  *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio 1.
Inadequate reporting of methods. 2.
One small study. Wide confidence interval.

What does the evidence say?
It is uncertain whether high intensity case management reduces homelessness for recently released criminal offenders compared to another intervention (very low certainty).

1.A.4. High intensity case management (with consumer case managers) compared to high intensity case management (with non-consumer case managers)
In the study (76) that compared assertive community treatment with consumer case management to assertive community treatment with case management, the assertive community treatment model was similar in both interventions with slight differences in frequency of meetings between the teams. The main difference was that the consumer team had between none and 11 previous psychiatric hospitalizations and the non-consumer team had no hospitalizations. There was no difference in the number of 15-minute time units of services the first year of the program between the two teams, however consumer case managers provided more services in person to their clients and less office-based services. Participants were recruited between 1990 and 1991.

Primary outcomes: Housing stability and homelessness
The results (76) show that 44 of a total of 90 participants lived in the same housing situation during the two year study period. Six participants (not specified from which group) reported being homeless at some point during the study. This study did not report any difference between the groups. There was no more data available and thus no outcomes for which we could assess certainty of the evidence (see GRADE Evidence profile in Appendix 8, The studies varied in terms of how the intervention was described. Studies were included in this category of interventions if the case management was included as part of the intervention, but the case management component was (a) not described as being intensive (e.g. assertive community treatment, intensive case management), or (b) was described as being or using components of brokered case management.
In the first study (47), the case management services included an occupational therapist consultant and participants were seen weekly for medication monitoring and money management. In the second study (64), the intervention was described as differing greatly according to the individual case manager in terms of time and services offered. At minimum, each participant received a needs assessment and the assessment with the person's carer (all participants were diagnosed with longterm mental disorders), assistance in meeting the identified needs, and monitoring of the participant's progress. The third study (74) examined the effect of three interventions: community reinforcement approach, motivational enhancement therapy and strengths based case management. We have chosen to focus on the case management intervention as the intervention group for this review. The case management intervention included case managers linking participants with resources in the community, securing needed services, focusing on the clients' strengths and giving the client high degree of responsibility. The fourth study (77) examined the effect of case management which was a hybrid between brokered case management and fullservices models. There was a focus on linking patients with services (medical, psychiatric, social, legal and social), arranging appointments and accompanying participants to appointments. In the fifth study (26), case management was provided for an average of 3 months and included ordinary case management services (not described) and provision of immediate tangible resources (e.g. transport tokens, food vouchers, medical care and rent deposits).
The case management interventions were compared to usual services (26, 64), case management without an occupational therapist (47), brief contact (77), or two other interventions that did not included case management or housing programs (74).

1.B.1. Low intensity case management compared to usual services
We found two studies that compared low intensity case management to usual services (26, 64) in the USA.

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The Campbell Collaboration | www.campbellcollaboration.org Usual services were described as services that are usually provided to individuals with substance abuse disorders after discharge from rehabilitation (26) or services that clients had been receiving prior to study enrolment (64).
The target populations in the two studies differed (individuals with long term mental illness and individuals with substance abuse disorders), which dictated the type of usual services the comparison groups received.

Primary outcomes: Housing status and homelessness
In the first study (64), participants in the intervention group reported a mean of 44.3 days in better housing during the 14 months prior to follow-up compared to 32.3 days for the control group. The intervention group also reported a mean of 15.1 days in worse housing compared to 33.4 days for the control group for the same time period. There was not enough information to assess the difference between groups.
In the second study (26), participants in the intervention group increased their residential stability by 9 days during the 60 days prior to the 12 month follow-up interview. No information was reported for the control group.
The results and quality assessments for low intensity case management compared to usual services are summarized in Table 7. The complete GRADE evidence profile is shown in Appendix 8,  What does the evidence say? It is uncertain whether low intensity case management compared to usual services improves housing stability and/or reduces homelessness (very low certainty evidence).

1.B.2. Low intensity case management with an occupational therapist compared to low intensity case management without an occupational therapist
We found one study (47) that compared low intensity case management to low intensity case management in the USA. In this study the comparison condition was identical to the intervention, but with a regular case manager instead of an Occupational Therapist (OT) as case manager.

Primary outcomes: Housing status
The authors of the study measured and report how the participants' current housing situation differs from their ideal housing standards according to an unspecified 13-point scale. The mean for the intervention group at 12 months was 1.04 below their ideal and for the control group 1.71 below their ideal housing situation. The authors state that the average variance from ideal housing was lower at 12 months than at baseline for the intervention group (t(24)=-2.16, p=0.04) but there was no difference for the control group from baseline to 12 months.
The results and quality assessments for low intensity case management (with OT) vs low intensity case management (no OT) for homeless adults with mental illness are summarized in Table 8. The complete GRADE evidence profile is shown in Appendix 8, Table 6.1.6. The intervention group reported less variance from ideal housing at 12 months than at baseline. There was no difference in variation from ideal housing for control group from baseline to 12 month follow-up.

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(1 RCT) ⨁◯◯◯ VERY LOW 1,2 *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval 1.
Risk of performance bias and reporting bias. Inadequate reporting of randomization and allocation concealment methods.

What does the evidence say?
It is uncertain whether low intensity case management compared to low intensity case management has an effect on the amount of time spent in ideal housing (very low certainty evidence).

1.B.3. Low intensity case management compared to other intervention (no case management or housing component)
We found two studies (74, 77) that compared low intensity case management to other interventions without case management or housing components in the USA.
A total of 460 participants were randomized to either case management (N=183) or another intervention (N=277). The participants were recruited between 1994 and 1996 (77) or between 2006 and 2009 (74).
In the first study (77) the comparison group received brief contact, which is described as one or two sessions with a counsellor with a ratio of approximately 100 participants to one case manager, which involved education about reducing HIV transmission and referrals to other services. The focus of the original study was to investigate brief contact. Case management was used in the control condition. However, we have only reported raw data here, and not the effect size as it was calculated and reported in the original publication. The type of comparison condition thus does not impact the results reported here. In the second study (74), the two comparison interventions were community reinforcement approach (CRA) and motivational enhancement therapy (MET). CRA is described as an operant-based behavioural intervention and focuses on building up skills (anger management, social and recreational counselling, and refusal skills training) within the community to achieve and maintain sobriety. MET is an adaptation of motivational interviewing and was described as lower frequency treatment compared to the other two interventions.

Primary outcome: Homelessness
Both studies reported outcomes related to homelessness. In the first study (77), the authors report the number of participants who reported being homeless at each follow-up point; however, the number of participants included in the analysis for each follow-up point is unclear. At 18 months 11.3% of participants in the intervention group and 13.8% participants in the comparison group reported being homeless.
In the second study (74), participants report the mean percentage of days homeless during the 90 days prior to each follow-up interview. It is not possible to report the findings from these studies in forest plots given the lack of information reported in the first study (77), and the comparison with two types of control conditions in the second study (74).

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The Campbell Collaboration | www.campbellcollaboration.org The results and quality assessments for low intensity case management compared to another intervention with no case management or housing component for youth and adults with substance abuse problems are summarized in Table 8. The complete GRADE evidence profile is shown in Appendix 8,   3,4 *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval 1.
Risk of performance bias. Inadequate reporting of methods.

3.
Inadequate reporting of blinding of participants and personnel and outcome assessors. 4.

What does the evidence say?
It is uncertain whether low intensity case management compared to another intervention with no case management or housing component has an effect for youth and adults with substance abuse problems.

Category 1C: Critical time intervention
In all three studies that examined the effect of Critical Time Intervention compared to usual services (56, 72, 79), the active part of the Critical Time Intervention was nine months; however the length of follow-up and after care activities in the three studies varied.

1.C.1. Critical time intervention compared to usual services
The three included studies targeted either single mothers living with at least one child between 18 months and 16 years and living in shelters with mental illness and/or substance dependence (72), or adults with severe mental illness who are homeless or at-risk of homelessness (56, 79).

Primary outcome: Homelessness
All three of the included studies examined the effect of critical time intervention compared to usual services on homelessness (56, 72, 79).
Results from these studies could not be pooled due to lack of details in reporting of results. In the first study (56), 58 participants from the intervention group and 59 from the control group were included in analyses. Homelessness was measured in two ways. First, participants reported via The Personal History Form ever versus never being homeless in the 18 weeks prior to the last follow-up interview at 18 months. Fewer participants in the intervention group experienced homelessness during this period (3/58) than in the control group (11/59 . Furthermore, the authors reported that the difference between the two groups seemed to widen between after the active part of the intervention ended (i.e. between 9 and 18 months). This study also reports the number of non-homelessness nights during the study period (mean number of days reported each month up to 18 month follow-up). The intervention group reported more nights in housing (not homeless) (M= 508.0, SD=60) than the control group (M=450, SD=139) (MD=58, t=2.64, df=64, p=0.01).
In the third study (72), participants were followed for 15 months. The authors reported the length of time to leave shelter, and the number of days before moving into stable housing. Reports were given using a structured residential follow-back instrument. More families in the intervention group (N=97) left shelter than in the control group (N=113), and the transition from shelter to housing occurred faster with the intervention group. The intervention group used a mean number of 91.25 days (SD=82.3) to first move into stable housing compared to a mean of 199.15 days (SD=125.4) for control group participants. The majority of the intervention group was rehoused after two to three months compared to five months for the control group.
The results and quality assessments for critical time intervention compared to usual services are summarized in Table 10. The complete GRADE evidence profile is shown in Appendix 8, Table  8.1.8. *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; OR: Odds ratio; MD: Mean difference 1.
Risk of selection bias and performance bias.

3.
Risk of selection bias in one study. Risk of performance bias in both studies. Inadequate reporting of randomization and allocation concealment methods in one study.

5.
Risk of performance bias. Inadequate reporting of randomization and allocation concealment methods. 6.
Inadequate reporting of blinding methods. Risk of reporting bias.

What does the evidence say?
Critical time intervention compared to usual services for adults with mental illness: • May lead to little or no difference in the number of people who experience homelessness (low certainty evidence). • May lead to fewer days spent homeless (low certainty evidence).
• May lead to more days spent not homeless (low certainty evidence).
• May reduce the amount of time to leave a shelter (and move to independent housing) (low certainty evidence).

Description of the included studies
We found six studies with eight comparisons on the effects of abstinence-contingent housing programs (26, 58, 66-68, 75). All of the included studies were conducted in the USA. The data for the included studies were collected between 1991 and 2004. Within the category of abstinencecontingent housing programs, we identified three subcategories (see Table 11). The above interventions are compared to usual services, or other interventions. That is, abstinencecontingent housing is compared to another active intervention. Table 12 presents an overview of the populations, interventions, comparisons and outcomes in the six included studies. In some studies the duration of the intervention is reported and differs from the longest follow-up point. In these instances we have reported both the duration of the intervention and the longest follow-up point.

Description of the intervention
All of the interventions in the included studies had some component of abstinence-contingent housing. Abstinence-contingent housing in the included studies consisted of program-provided housing for a set period of time (6-8 months) with or without some rent contributed by the participants after the initial phase. Conditionality of tenancy for the participants consisted of a contract agreeing to abstinence and then regular urine testing to screen for substance use. Housing for participants was not segregated (segregated housing is separated from the general public and only for individuals receiving social assistance).

Category 2A: Abstinence-contingent housing with case management
We found one study (26) with two comparisons that examined the effect of abstinence-contingent housing with case management in the USA. Participants were recruited from 1991 to 1992 and randomized to one of three groups: abstinence-contingent housing with the progressive independence model of case management (ACH+CM), the progressive independence model of case management only (CM), or usual services (US).
The abstinence-contingent housing component consisted of supported housing in low-income apartment blocks where tenancy was contingent upon following program rules (26). The case management component in this study was described as a "progressive independence model" with a focus on providing immediate tangible resources while supporting further treatment for substance abuse and other relevant problems. Case management was also contingent on following a contract which participants signed before the start of the intervention.
Participants in the case management condition received an average of three months care, while participants in the housing with case management condition received an average of six months of care.
Abstinence-contingent housing with case management was compared to usual services (26) and case management only (26). Usual services consisted of aftercare services such as referrals to outpatient or inpatient substance abuse agencies or welfare offices.

2.A.1. Abstinence-contingent housing with case management compared to usual services
One study (26) examined the effect of abstinence-contingent housing with case management compared to usual services.

Primary outcome: Housing stability
Results from the included study (26) show that participants in the intervention group reported more days in housing than participants in the control group at the 12 month follow-up interview (MD=6.4, 95% CI= 6.18 to 6.62). The results for abstinence-contingent housing with case management compared to usual services only are presented in Table 12. The results are controlled for length of time from baseline to the second follow-up interview, which varied due to difficulties arranging meetings with participants and the number of days in the relevant period spent in a controlled environment (e.g. prison or hospital) since they are not truly homeless or housed during this time. Other control variables such as characteristics which were found to vary across the treatment conditions are also controlled for (being recruited from a particular short-term program, reported perception of health problems at baseline, access to an automobile, having ever been married, having foster care experience as a child or having lived with one's mother continuously until 18). Not enough information was provided to present the results in a forest plot.
The results and quality assessments for abstinence-contingent housing with case management compared to usual services are summarized in Table 13. The complete GRADE evidence profile is shown in Appendix 8,  Fewer than 400 participants.

What does the evidence say?
It is uncertain whether abstinence-contingent housing with case management compared to usual services leads to a difference in number of days spent in in stable housing (very low certainty evidence).

2.A.2. Abstinence-contingent housing with case management compared to case management
One study (26) compared abstinence-contingent housing with case management to case management only.

Primary outcome: Housing
Results from this study (26) show that participants in the intervention group (N=108) reported a mean increase of 25.6 days housed of the previous 60 days from baseline to 12 months compared to a mean increase of 21.2 days for the comparison group (N=70). Not enough information was reported to determine if there is a difference between groups, or to present the results in a forest plot.
The results and quality assessments for abstinence-contingent housing with case management compared to case management only is summarized in Table 14. The complete evidence profile is presented in Appendix 8,  Fewer than 400 participants.

What does the evidence say?
It is uncertain whether abstinence-contingent housing with day treatment compared to case management only leads to a difference in the number of days spent in stable housing (very low certainty evidence).

Category 2B: Abstinence-contingent housing with day treatment
Three studies evaluated the effect of abstinence-contingent housing with day treatment in USA (58, 66, 67).
The abstinence-contingent housing with day treatment intervention consisted of two general components: housing programs in which tenancy is conditional upon maintained sobriety and/or treatment, and day treatment (58, 66, 67).
In one study with two comparisons (58), participants were required to pay to remain in housing (but were not removed if unable to pay). The housing component in this study was only part of treatment and available for a maximum of six months. No information was available regarding segregation of the housing or whether it was individual or group housing.
In the second study (67), participants' tenancy in program management housing was contingent on abstinence. No information was provided in this study regarding rent payment, or the form of housing provided.
In the third study (66), participants were moved into rent free and furnished housing provided by the program after achieving abstinence. Participants in this study received segregated group or individual housing. After phase I half of the clients remained in this housing arrangement, and half moved to program-managed individual houses.

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The Campbell Collaboration | www.campbellcollaboration.org In these three included studies (58, 66, 67), participants in the intervention group received day treatment in the first phase of a two phase intervention. The second phase of the intervention included abstinence-contingent work therapy with minimum wage which could be used towards rent payments. Some participants also received aftercare (58) (66). Formal treatment ended after six months (58, 67, 68).

2.B.1. Abstinence-contingent housing with day treatment compared to usual services
One study compared abstinence-contingent housing with day treatment to usual services (67).

Primary outcome: Homelessness
Results from the included study (67) showed that participants in the intervention group reported a mean of 52 fewer days homeless in the previous 60 days at 12 month follow-up than in the previous 60 days at baseline. There was no change in number of days homeless for the control group.
The results and quality assessments for abstinence-contingent housing with day treatment compared to usual services is summarized in Table 15. A complete GRADE evidence profile is shown in Appendix 8,  The mean change in number of days homeless in past 60 days from baseline to 12 months was 0 for the control group. The intervention group had a mean change of 52 fewer days homeless from baseline to 12 months, p=0.026.

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(1 RCT) ⨁⨁◯◯ LOW 1,2 *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval 1.
Risk of performance bias and attrition bias.

What does the evidence say?
Abstinence-contingent housing with day treatment compared to usual services may lead to fewer days spent homeless (low certainty evidence).

2.B.2. Abstinence-contingent housing with day treatment compared to day treatment
Two studies (58, 66) examined the effect of abstinence-contingent housing with day treatment compared to day treatment.
Participants in the comparison groups received day treatment only which was similar to the day treatment offered to the intervention group for months 1-2 and 3-6 (58, 66). These participants were not offered housing. When the results were pooled using SMD, I 2 =86%. Since this heterogeneity could not be explained, we chose not to pool the results ( Figure 8). The results and quality assessments for abstinence-contingent housing with day treatment compared to day treatment only is summarized in  Less than 400 participants.

What does the evidence say?
It is uncertain whether abstinence-contingent housing with day treatment compared to day treatment only leads to a difference in number of days spent in stable housing or employed (very low certainty evidence).

2.B.3. Abstinence-contingent housing with day treatment compared to nonabstinence-contingent housing with day treatment
One study examined the effects of abstinence-contingent housing with day treatment compared to non-abstinence contingent housing with day treatment (58). The comparison group consisted of an equivalent intervention as the abstinence-contingent housing group; however, continued tenancy was not dependent on sobriety (i.e. the results of the urine tests). Both groups received the day treatment component.

Primary outcome: Housing stability
Results from this study (58) showed that participants in the intervention group reported a greater increase in the number of days in stable housing in the 60 days prior to follow-up between baseline and follow-up (12 months) (MD=17.7 (SD=33.8)) than participants in the control group (MD=14.2 (SD=31.7)).
The results and quality assessments for abstinence-contingent housing day treatment compared to non-abstinence-contingent housing with day treatment for housing stability and homelessness are summarized in Table 17. A complete GRADE evidence profile is shown in Appendix 8,  Less than 400 participants.

What does the evidence say?
It is uncertain whether abstinence-contingent housing with day treatment compared to nonabstinence-contingent housing with day treatment leads to a difference in number of days spent in stable housing (very low certainty evidence).

2.B.4. Abstinence-contingent housing with day treatment compared to abstinencecontingent housing with community reinforcement approach
We found two studies that examined the effect of abstinence-contingent housing with day treatment compared to abstinence-contingent housing with community reinforcement approach (68, 75) in the USA.
Participants in one study (68) were provided with a furnished and rent free apartment and vocational training which was contingent on continued sobriety during phase I (weeks 2-8). In Phase II (weeks 3-24) participants were required to pay a small amount of rent (not specified) from program provided stipends. Participants who maintained abstinence were moved to a transitional housing program. In Phase III (week 25-end) continued tenancy in abstinence-contingent program housing was only available when space was available at a modest rent.
In the other study (75), participants were housed in grant-supported housing for a maximum of three months contingent on sobriety. However, participants who had secured a job and saved a pre-set amount of money could stay one additional month.

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The Campbell Collaboration | www.campbellcollaboration.org In both studies, participants in the comparison groups received the same abstinence-contingent housing, vocational training and work therapy as participants in the intervention group, with the community reinforcement approach in addition.

Primary outcomes: Homelessness and stable housing
Homelessness was reported in one study (75). The rate of homelessness for participants in the intervention group (N=64; 13.7%) was lower than for the control group (N=42; 34%) at four months. There was little or no difference between groups (when reported at all) at the other followup points.
Two studies reported outcomes related to stable housing. In one study (75), more participants from the CRA group (62.5%) were paying for housing (rather than staying with friends or in a motel) at the 12 months follow-up than in the day treatment group (44%) (χ² (1, N=80)=2.73, p<0.10).
In the second study (68), a greater proportion of participants in the abstinence-contingent housing with CRA group (N=103; 44.7%) were housed more than 40 of the previous 60 days at 18 months than in the abstinence-contingent housing with day treatment group (N=103; 35.6%). There was also a greater increase in proportion of participants housed 40 of the previous 60 days from baseline to 18 months in the CRA group (36%) than in the day treatment group (25.7%).
Not enough data were reported to assess whether there was a difference in time spent in stable housing between the two groups. Furthermore, the outcomes were reported too differently in the two studies to pool the results.
The results and quality assessments for abstinence-contingent housing with day treatment compared to abstinence-contingent housing with community reinforcement approach is summarized in Table 18. A complete GRADE evidence profile is shown in Appendix 8, Table 8.2.6.  Proportion of participants housed more than 40 of past 60 days assessed with: Retrospective Housing, Employment and Substance Abuse Treatment Interview (RHESAT) follow up: 18 months A greater proportion of participants in the intervention group (44.7%) were housed more than 40 of the previous 60 days at 18 months than in the control group (35.6%). Furthermore, there was a greater increase in pro-portion of participants housed 40 of the previous 60 days from baseline to 18 months in the intervention group (36%) than in the control group (25.7%). -

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(1 RCT) ⨁◯◯◯ VERY LOW 2,3 *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval 1.
Risk of detection and selection bias. Inadequate reporting of allocation concealment methods.

3.
Risk of detection bias, selection bias, and performance bias.

What does the evidence say?
It is uncertain whether abstinence-contingent housing with day treatment compared to abstinencecontingent housing with community reinforcement has an effect on the amount of time spent homeless or in stable housing (very low certainty evidence).

Description of the included studies
We identified eight studies that evaluated the effect of non-abstinence-contingent housing (24, 42, 43, 55, 58, 65, 73, 78). Most of the included studies were from the USA (N=6); however, the largest study was from Canada (N=1). Data for the included studies were collected between 1997 and 2013. Within the category of non-abstinence-contingent housing programs, we identified two subcategories (see Table 19). These interventions are compared to usual services or other interventions. Table 20 presents an overview of the populations, interventions, comparisons and outcomes in the included studies.

Description of the intervention
Non-abstinence-contingent housing includes a variety of interventions that provide housing to homeless persons without any conditionality attached to their stays (such as abstinence, treatment attendance, etc.). Four of the included studies examined Housing First (with case management), which encourages early placement in stable housing after staying in transitional housing for a short period of time. The other studies examined supportive housing with assertive community treatment (65), staffed group homes with intensive case management (55), and non-abstinencecontingent housing with day treatment (58).

Category 3A: Housing First
We found four studies that evaluated the effect of Housing First (24, 42, 43, 78). In Housing First treatment and housing domains are considered as being closely linked, but separate domains. In other words, treatment is encouraged, but refusal does not result in removal from housing. The emphasis in Housing First is on consumers' choice (i.e. the consumer helps to define and plan goals). A central component is that housing is immediately provided if desired, and tenancy is not contingent on adherence to treatment schedules or sobriety. All four studies had two program requirements: tenants had to pay part (30%) of their income (usually Supplemental Security Income) toward the rent by participating in a money management program, and tenants had to meet with a staff member regularly.
One study had three intervention arms and compared two models of the Housing First program (Pathways to housing and Consortium) to usual services (78). As part of the Housing First interventions, participants were offered the ACT model of case management which involves intense case management with a team of professionals that are available 24 hours a day, seven days a week (24, 42, 78). Participants in the second study (24) received the Pathways to Housing model which adds modifications to standard ACT: a nurse practitioner was added to the team to address health problems, and a housing specialist joined the team to coordinate the housing services (24). In the third study (42), participants were divided according to mental health needs (high or moderate) and while the high needs participants received ACT, the moderate needs participants received intensive case management together with Housing First. In the fourth study (43), participants in the intervention group received Housing First with case management (case managers had less than 20 clients each). 63 The Campbell Collaboration | www.campbellcollaboration.org Housing in the included studies was provided as group living arrangements or apartments at single and scattered sites (43), or scattered sites only (24, 42, 78).

3.A.1. Housing First compared to usual services
Three studies (42, 43, 78) examined the effect of Housing First on housing stability and homelessness compared to usual services in Canada (42) and the USA (43, 78).
In all three studies the intervention was compared to usual services. Usual services included having access to other housing and support services through other programs in their communities. In one study, however, (78) two groups of participants received a version of the Housing First intervention -either the Pathways to Housing model which is a well-established model, but new to this particular community, or the Consortium model, which was made up of a consortium of treatment and housing agencies who had no prior experience of operating Housing First (78). The authors also report differences between these two groups.
The included studies reported number of days homeless, in shelter, in respite care, with family/friends, or in paid housing (43), proportion of time homeless (in shelters or on street) and stably housed (42), housing stability (proportion of time housed) (42), and number of participants in stable housing at end of study (78).

Primary outcomes: Housing stability and homelessness
The first study (42) examined housing stability in two ways: proportion of time during the last 6 months of the study that participants reported being housed all of the time, some of the time or none of the time, and percentage of days spent in stable housing for each three month period of follow-up. Sixty-two percent of participants receiving Housing First reported being housed all of the time compared to 31% of participants who received usual services; 22% of Housing First participants were housed some of the time and 16% none of the time compared to 23% and 46%, respectively, of usual services participants. For the second outcome, Housing First participants were in stable housing an average of 73% of the time compared to an average of 32% the time for participants who received usual services. We were not able to calculate difference between groups due to insufficient reporting of results in the primary study.
This study (42) also reported proportion of time in different types of shelter over the study period: Participants in the Housing First group spent approximately 12% of time in temporary housing, 6% in emergency shelters, 9% in institutions and 3% on the street compared to participants in the usual service group who spent approximately 33% of time in temporary housing, 16% in emergency shelters, 11% in institutions and 8% on the street. We were not able to calculate difference between groups due to insufficient reporting of results in the primary study. 64 The Campbell Collaboration | www.campbellcollaboration.org In the second study (43), number of days homelessness was reported at each three month interval follow-up point and accumulated over the 18 month study period. The results were then annualized (converted to a rate for one year). Participants in the Housing First group reported fewer days homeless than participants in the usual services group ((MD=-62.3 (SE=12.4), p<0.05) and more days in paid housing (MD=109.9 (SE=8.7), p<0.05) at 18 month follow-up.
In the third study (78), 103 of 209 participants in the Housing First group were placed in permanent housing at the 20 month follow-up compared to 13 of 51 participants in the case management only group.
We were unable to pool results from the included studies due to difference in how the outcomes were reported.
The results are shown in Table 21. The results and quality assessments for Housing First compared to usual services are summarized in Table 22. The complete GRADE evidence profile is shown in Appendix 8, Table 8.3.1. Risk of performance bias and detection bias.

3.
Risk of selection bias and attrition bias. 4.

What does the evidence say?
Housing First compared to usual services: • Probably reduces the number of days spent homeless (moderate certainty evidence).
• Probably reduces the proportion of time an individual spends homeless (moderate certainty evidence). • Probably increases the number of days in paid housing (moderate certainty evidence).
• Probably increases the proportion of time in stable housing (moderate certainty evidence).
• May increase the number of people placed in permanent housing after 20 months (low certainty evidence).

Subgroup analysis
In one study participants were stratified according to mental health needs (42). The authors conducted sub-group analyses where participants with high support needs for mental health services (high needs) and participants with moderate support needs for mental health services 66 The Campbell Collaboration | www.campbellcollaboration.org (moderate needs) were examined separately (42). All five sites are included in the high needs analysis, but only four sites are included in the moderate needs analysis because one site did not separate participants according to need level.
High needs participants received Housing First with Assertive Community treatment while moderate needs participants received Housing First with intensive case management. Both groups were compared to participants who received usual services. For participants with high support needs, those receiving Housing First with assertive community treatment reported a greater mean proportion of time in stable housing over the 24 month study period (71%) than the control group (29%) (adjusted absolute difference AAD=42%, 95% CI 28% to 45%, p<0.01) (42).
For participants with moderate support needs, those receiving Housing First with intensive case management had a higher proportion of days stably housed than the control group across all four included study sites (a summary statistic for the total group of participants across sites was not reported).
Stefancic 2007 (78) also examined the difference between the two models of Housing First included in the study in number of clients placed in permanent housing. Sixty two of 105 participants in the Pathways to Housing group were placed and 52 of 104 in the Consortium group were placed. Housing retention rates were also reported for all participants: at the two-year followup point 84% of Housing First participants were housed compared to 88.5% of control group participants and after 47 months 68% were still housed compared to 78.3% of control group participants. Results of housing retention between the two Housing First groups shows that 88.5% of Pathways participants were still in housing compared to 79% of Consortium participants and 88.5% after two years and 78.3% of Pathways participants were in housing, 57% of Consortium participants after 47 months.

3.A.2. Housing First compared to abstinence-contingent housing
One study (24) examined the effect of Housing First compared to abstinence-contingent housing on homelessness in New York, USA.

What does the evidence say?
It is uncertain if Housing First has an effect on homelessness or housing stability when compared with abstinence-contingent housing (very low certainty evidence).

Category 3B: Non-abstinence-contingent housing with treatment
We identified four studies that examined the effect of non-abstinence-contingent housing with some form of treatment (case management or day treatment) (55, 58, 65, 73). The studies were conducted in the USA. The interventions in these studies included provision of housing to participants in the treatment group that was not conditional on maintaining sobriety or attending treatment.
One study (55) compared non-abstinence-contingent housing in the form of group living arrangement versus independent living. Participants in both groups received housing and some form of case management (intensive case management with house staff for those assigned to group living arrangements and assertive community treatment for participants in the independent living group) (55). Participants in the intervention group could be assigned to one seven group homes which accommodated between six and ten participants and had shared amenities but separate bedrooms. The staffing patterns were similar to traditional group homes with live-in staff. The participants had an intensive case manager they met with at least once a week. They paid 30% of their income to cover rent and utilities and were encouraged to attend activities at community mental health centres (55).
In the second study (73), participants in the intervention group were offered temporary program managed shelter as well as intensive case management. Only program participants were housed in the shelter. The research team eventually began to develop their own housing as well. Shelter stay was not contingent on treatment or sobriety; however, a small group of participants were eventually required to enter a payee arrangement due to lack of progress and using their income for drug purchases (73).
In the third study (65), the intervention was described as "parallel housing" where participants are offered housing from "mainstream" (i.e. not segregated) options that were owned and operated by community landlords or housing agencies. Participants lived independently and their tenancy was not conditional on treatment participation. The participants are also offered assertive community treatment with high intensity (low client to case manager ratio and case managers are available 24 hours every day).
In the fourth study (58), participants in the intervention group received non-abstinence contingent housing with day treatment (58). The non-abstinence-contingent housing with day treatment intervention consisted of two components: housing programs in which tenancy is not conditional upon maintained sobriety and/or treatment, and day treatment. Participants were required to pay to remain in housing (but were not removed if unable to pay). The housing component was only part of treatment and available for a maximum of six months. No information was available regarding segregation of the housing or whether it was individual or group housing. Participants in the intervention group also received day treatment in the first phase of a two phase intervention. Day treatment lasted between 6.25 hours daily for the first two months of the study. Phase II of the intervention included abstinence-contingent work therapy with minimum wage. Some participants also received aftercare. Formal treatment ended after six months.

3.B.1. Non-abstinence-contingent housing with high intensity case management compared to usual services
One study (73) evaluated the effect of non-abstinence-contingent housing with high intensity case management compared to usual services on housing stability, homelessness, quality of life and psychological status.
Control group participants were offered usual services provided by the city.

Primary outcome: Homelessness
One study (73) evaluated the effect of non-abstinence-contingent housing on homelessness and housing. The rate of decline in amount of time spent living on the streets over the 24 months study period was almost twice as great for the intervention group (MD=-54.9 (SD=36.9) that the control group (MD=-28.2 (SD=44.5)) (t=4.18, p=0.001). Individuals in the intervention group reported more time in shelters, specifically the program provided respite housing than the control group 69 The Campbell Collaboration | www.campbellcollaboration.org (MD=23.1 (SD=29.27 compared to MD=2.8 (SD=15.23), p=0.001). While participants in both groups increased the time spent in community housing (including transitional settings, long-term settings), the rate of increase was almost twice as great for the intervention group (MD=21.0 (SD=30.39)) than the control group (MD=9.9 (SD=32.34)) (t=-2.27, p=0.025). At the final followup point 38% of the intervention group were in community settings compared to 24% of the control group.
The results and quality assessments for non-abstinence-contingent housing with high intensity case management compared to usual services are summarized in Table 24. The complete GRADE evidence profile is presented in Appendix 8,   Fewer than 400 participants.

What does the evidence say?
Non-abstinence-contingent housing with high intensity case management compared to usual services: • May lead to greater decrease in proportion of time spent homeless or in shelter (low certainty evidence).
• May increase the amount of time in community living arrangements (low certainty evidence).

3.B.2. Non-abstinence-contingent group living arrangements with high intensity case management compared to non-abstinence-contingent independent apartments with high intensity case management
One study (55) evaluated the effect of non-abstinence-contingent group living arrangements with high intensity case management (NACHG) compared to non-abstinence-contingent independent apartments with case management (NACHI) on housing stability, homelessness, and satisfaction with life.
Participants in the comparison group were placed in non-abstinence-contingent independent apartments. These apartments were efficiency units operated by the local housing authority and participants were offered voluntary weekly group meetings, but not other programming on-site.

Primary outcomes: Housing stability and homelessness
The included study examined the effect of non-abstinence-contingent group living arrangements on the number of days homeless during the study period and number of days homeless after rehousing (55). A total of 110 participants were included in the analysis for outcomes measured at final follow-up (18 months) (intervention N=61; comparison N=49). There was little or no difference in housing status between groups at 18 months. Participants in the intervention group reported a mean of 43 days homeless over 18 months compared to a mean of 78 days for the control group. We could not calculate the difference between groups due to inadequate reporting in the primary study.
The results and quality assessments for non-abstinence-contingent group living arrangements with high intensity case management compared to non-abstinence-contingent independent apartments with high intensity case management are summarized in Table 25. The complete GRADE evidence profile is shown in Appendix 8,  *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio 1.
Inadequate reporting of randomization, allocation concealment and blinding. 2.

What does the evidence say?
Non-abstinence-contingent group housing with high intensity case management compared to nonabstinence-contingent independent apartments with high intensity case management • May lead to fewer days homeless after being rehoused and reduce the number of days spent homeless (low certainty evidence).
• It is uncertain if the intervention has an effect on housing status at 18 months (very low certainty evidence).

3.B.3. Non-abstinence-contingent housing with high intensity case management compared to abstinence-contingent housing with high intensity case management
One study (65) evaluated the effect of non-abstinence-contingent housing with high intensity case management compared to abstinence-contingent housing with high intensity case management on housing stability and homelessness in USA.
In this study (65), the intervention ("parallel housing") was compared to "integrated housing". The main difference according to the researchers is (1) housing control: integrated housing is owned or leased by the mental health provider; (2) integration within the community: parallel housing is not segregated housing units while integrated housing is; (3) conditionality: integrated housing is often linked to treatment participation, and (4): live-in staff: integrated housing sometimes contain livein staff.

Primary outcomes: Homelessness and housing stability
The included study (65) reported proportion of time functionally homeless (a term used by primary authors to describe both time literally homeless and days in temporary or institutional settings that are preceded and followed by days homelessness) and housing stability (stable housing defined by authors as one's own apartment/house, single room occupancy with or without services, family or friends' house on a long-term basis, boarding house, transitional housing or a group home).
Only 121 participants took part in either the intervention (N=60) or the comparison group (N=61). Participants in both groups reduced the number of days functionally homeless from baseline to 18 months, however there was a greater change in number of days homeless among members of the comparison group over the study period (F=6.07, p<0.05, d=-0.52). At the end of the study 68.1%

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The Campbell Collaboration | www.campbellcollaboration.org of participants in the intervention group were in stable housing compared to 85.5 % of comparison group participants (F=5.99, p<0.05, d=0.51).
The results and quality assessments for non-abstinence-contingent housing with high intensity case management vs abstinence-contingent housing with high intensity case management are summarized in Table 26. The complete GRADE evidence profile is shown in Appendix 8, Table  8.3.5.

(1 RCT)
⨁◯◯◯ VERY LOW 1,2 *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval 1.
Risk of attrition bias. Inadequate reporting of randomization, allocation concealment and blinding. 2.

What does the evidence say?
It is uncertain whether non-abstinence-contingent housing with high intensity case management compared to abstinence-contingent housing with high intensity case management has an effect on housing stability (very low certainty evidence).

3.B.4. Non-abstinence-contingent housing with day treatment compared to day treatment
One study (58) evaluated the effects of non-abstinence-contingent housing with day treatment compared to day treatment only on housing stability and homelessness in the USA.
Participants in the control condition received day treatment only with no provision of housing. The results and quality assessments for non-abstinence-contingent housing with day treatment compared to day treatment are summarized in Table 27. The complete GRADE evidence profile is presented in Appendix 8, Table 8.3.6. The mean changes in mean days housed in past 60 days between baseline and 12 months was 9.5 days The mean changes in mean days housed in past 60 days between baseline and 12 months in the intervention group was 4,7 days more (9,38 fewer to 18,78 more) *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; MD: Mean difference 1.
Risk of selection bias and attrition bias. Inadequate reporting of allocation concealment methods and blinding. 2.

What does the evidence say?
It is uncertain whether abstinence-contingent housing with day treatment compared to day treatment only leads to more days in stable housing (very low certainty).

Category 4: Housing vouchers with case management Description of included studies
We identified four studies with five comparisons that evaluated the effect of housing vouchers with case management (27, 62, 71, 81).

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The Campbell Collaboration | www.campbellcollaboration.org Table 28 presents an overview of the populations, interventions, comparisons and outcomes in the included studies.

Description of the intervention
Housing vouchers for the purpose of this review is interventions where the housing component is limited to the provision of financial assistance for housing of the participants choosing. Case management is described above (Category 1).
In the first study (27), 362 participants were assigned to one of four groups: comprehensive case management or traditional case management with or without HUD Section 8 housing certificates (financial assistance). A preliminary analysis of the between group differences showed no correlation between the case management model and housing outcomes, so further analysis was based on the Section 8 housing certificate condition. Therefore the groups were analyzed as following: Comprehensive or traditional case management with HUD Section 8 housing certificates compared to comprehensive or traditional case management without HUD Section 8 housing certificates. Participants in each condition received a range of case management services varying in intensity (time between contact with case managers), case load of case managers (1:22 up to 1:40), and availability (comprehensive case managers were constantly available). The HUD Section 8 housing certificate is a program allowing holders to pay a fixed 30% of their adjusted income for a private rental unit of their choosing. There are no conditions on the tenancy except for that the housing must meet the quality standards of the US Department of Housing and Urban 76 The Campbell Collaboration | www.campbellcollaboration.org Development and the rent for the unit must be equal or less than fair market rent for the area. The participants in this program received a tailored version of the certificate program with more flexible rules (for example keeping appointments) and with support from housing specialists who assisted with the application process and were sensitive to limitations imposed by severe mental illness.
In the second study (62), participants in the intervention group were enrolled in the Home to Stay program. The Home to Stay model was designed to quickly put families into housing and maintain the housing using a time-limited financial subsidy and temporary support services. At the beginning of the study participants could access 1 year Advantage housing subsidies (three types of locally funded subsidies intended for families with children, clients with disability payments, or employed clients). After three months, clients (participants) were required to contribute 30% of their monthly income and eligibility was restricted to employed (or receiving federal disability payments) adults with children. At the one year mark these subsidies were no longer available for new families and two years after the study began the monthly payments were terminated for all recipients. Initial services in the Home to Stay program was to help families' secure permanent housing and exist shelter quickly. After they were placed in housing, there was a focus on obtaining employment (income) equal to double the family's rent obligation and/or obtaining a permanent housing subsidy. Participants in this group also received fairly intensive case management services while in shelter. The intervention condition was different than the usual services condition specifically with respect to more frequent case manager contact, smaller caseloads, flexible scheduling, integrated help with financial literacy and continuing the services from shelter into housing.
In the third study (71) the US Department of Housing and Urban Development allocated funds for 1000 vouchers for a program providing housing and case management for literally homeless veterans with mental illness or substance dependence. These participants were offered priority access to the Section 8 housing vouchers (difference between 30% of their adjusted income and the lesser of Fair Market Rent or the unit rent). Case managers put the veterans in contact with the local housing voucher and helped them to locate an apartment, negotiate the lease, furnish and move into the apartment. The case management component was a modified assertive community treatment model (larger caseloads and encouragement of clients to use other Veteran Affairs health services). The intervention was compared to usual services and case management. Participants in the comparison conditions received standard Veteran Affairs homeless services, including shortterm brokered case management, or intensive case management.
In the fourth study (81), participants living with HIV/AIDS were provided with long-term rental housing assistance. The amount was determined by The Department of Housing and Urban Development (HUD) annually for each metropolitan area. Each person receiving rental assistance was required to pay 30% of this monthly adjusted income. Study-funded housing referral specialists assisted with finding housing and negotiating leases and participants received referrals to other supportive services.

Housing vouchers with case management compared to usual services
Two of the three studies that compared housing vouchers with case management to usual services (62, 71, 81) included multiple cities (71, 81). One study included families (62) and one study included adults living with HIV/AIDS.

Primary outcomes: Time to exit shelter, stable housing, homelessness
Three of the included studies evaluated the effect of housing vouchers compared to usual services on housing stability and homelessness (62, 71, 81). The studies measure and report these outcomes in such different ways that we are unable to pool results. The following is a narrative summary of the results from the three studies.
In the first study (62), the authors included work-based subsidies as a covariate in all analyses of differences between the intervention group (N=138) and the control group (N=192). A survival analysis using Cox regression of time to first exist from shelter (at least 30 days away from shelter) shows that the intervention group experienced fewer days to exit shelter (x 2 1 = 6.068, 95% CI = 0.589 to 0.942; proportional hazards assumption not violated). The authors also report the time to return to shelter (overnight stay) for those that did return (N=298) and that the intervention group reported longer time to return to shelter than the control group (x 2 1 = 6.524, 95% CI = 0.379 to 0.880; proportional hazards assumption not violated).
In the second study (71), data for 182 participants in the intervention group and 188 participants in the control group were reported related to number of days housed during the 90 days prior to each follow-up. We report the longest follow-up at 36 months. The intervention group reported more days housed (M=59.39) compared to the control group (M=47.60) (t=4.88, p<0.001). The intervention group also reported fewer days homeless (M=13.05) than the control group (M=20.45) (t=3.56, p<0.001).
In the third study (81), the authors reported the number of participants in their own home, the number living temporarily with others or in transitional settings, or the number with one or more nights homeless during the 90 days prior to follow-up for the intervention group (N=315) and the control group (N=315). At the 18 month follow-up interview there were more people from the housing vouchers group living in their own home (82.48) than the control group (50.58), fewer people in the housing vouchers group living temporarily with others or in transitional settings (14.96) than the control group (44.40) and half as many who reported being homeless at least once during the previous 90 days (2.55) than the control group (5.02). It is not possible to calculate the effect size due to lack of information reported in the results from the primary study.
The results and quality assessments for housing vouchers with case management compared to usual services are summarized in Tables 29. The complete GRADE evidence profile is shown in Appendix 8,  *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval 1.
Risk of performance bias and detection bias. Inadequate randomization methods.

What does the evidence say?
Housing vouchers with case management compared to usual services for homeless families: • May reduce the number of days it takes to leave tempoary shelters and increase the number of days before returning to temporary shelters (low certainty evidence). • May increase the number of days in stable housing and reduce the number of days spent homeless (low certainty evidence). • May increase the proportion of people living in their own house, reduce the proportion of people who experience at least one night of homelessness and reduce the proportion of people who live in transitional settings at 18 month follow-up (low certainty evidence).

Housing vouchers with case management compared to case management only
We identified two studies that examined the effect of housing vouchers with case management compared to case management (27). The case management component of the intervention varied in intensity. In one study, participants received either comprehensive (high intensity) case management or traditional (low intensity case management) in addition to the housing vouchers while the control group also received one of the two types of case management. Participants in the second study received high intensity case management. We have decided to combine the two studies under a broader heading of case management.

Primary outcomes
The first study (27)  . Finally, the authors also measured the proportion of participants who transitioned early into independent and community housing (the first 6 months). The authors reported that participants with housing vouchers stabilized in independent housing faster than participants in the comparison condition and were 8.4 times more likely to obtain independent housing in the first six months of the study (91/115 intervention group participants compared to 25/99 comparison group participants). On the contrary, the comparison group was 3.4 times more likely to obtain other types of community housing in the first six months (28/99 comparison group participants compared to 4/115 intervention group participants).
The results and quality assessments for housing vouchers with case management compared to case management only are summarized in Table 30, and the complete GRADE evidence profile is shown in Appendix 8,  *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio 1.
Inadequate reporting of methods.

2.
Risk of performance bias. Inadequate reporting of methods for blinding of outcome assessors. 3.

What does the evidence say?
Housing vouchers with case management compared to case management only • May increase the number of people living in independent housing and reduce the number of people living in community housing (low certainty evidence). • May increases the number of days spent in stable housing and reduces the number of days spent homeless (low certainty evidence). • May lead to no difference in the number of people living variable housing situations (low certainty evidence).

Category 5: Residential treatment Description of included studies
We identified two studies that evaluated the effect of residential treatment (49, 63). Both studies were conducted in the USA. Table 31 presents an overview of the populations, interventions, comparisons and outcomes in the included studies.

Description of the intervention
The two studies that evaluated the effect of residential care on homelessness and housing stability (49, 63). The interventions in the included studies are different due to the different populations which they target. In the first study (49), the intervention was divided into two phases: the residential phase (0-6 months) and the community phase (7-12 months). During the residential phase participants received case management services, treatment planning and service referral, counselling, and material assistance. During the community phase participants were placed in community living with continued case management and cognitive behavioural therapy and selfhelp groups such as Alcoholics and Narcotics Anonymous. Participants were followed up to 24 months, even though the active part of the intervention only lasted 12 months.
In the second study (63), participants were placed in a non-profit supportive housing program which used single rooms in an urban hotel. This permanent residence provided services such as a furnished room, case management, coordination of public assistance, medication and money management, meals, therapy and referrals to appropriate services. Both the treatment and the longest follow-up time was 12 months.

Residential treatment compared to usual services
We found two studies that evaluated the effect of residential care compared to usual services (49, 63).
While both studies compared the intervention to usual services, these services differed due to the different target populations in the studies. In the first study (49), the usual services was inpatient treatment in hospital wards for two to three weeks and included substance abuse education, 82 The Campbell Collaboration | www.campbellcollaboration.org therapy, self-help services, medical care, material assistance and referral to appropriate services. Customary community care was provided up to 12 months and included services as needed, halfway houses and mental health treatment for post-traumatic stress disorder.
In the second study (63), participants in the usual services condition received standard postdischarge care, of which one quarter of participants refused. No further information was provided on what this care entailed.
Due to the difference in population, intervention and comparison group characteristics we have not pooled the results. We present a narrative summary of the results from each study below.

Primary outcomes: Homelessness and stable housing
Both of the included studies reported the proportion of nights spent homeless ((49, 63). In the first study (49), participants in the intervention group (N=178) reported less homelessness than the control group (N=180) during the 60 days prior to the 24 month follow-up interview (11% compared to 2% for the control group) (Random effects regression estimate=0.104 (SE=0.037), Z=2.846, p=0.004). In the second study (63), participants in the intervention group reported less time homeless over the 12 month study period (6% SD=22 compared to 46% SD=51; t 2 =2.62, df=31, p=0.019). Furthermore, the authors report that during the study period, participants in the intervention group had a 13% chance of having 30 or more consecutive nights homeless compared to 39% for the control group (x 2 =87.46, df=1, p=0.01).
The first study (63) also reported the proportion of time participants reported being housed. Participants in the intervention group (N=26; 79%, SD=26) reported being in permanent housing more than twice as much as the control group (N=23; 33% SD=36) during the study year (t 2 =4.32, df=32, p=0.0001). Furthermore more than twice as many participants from the intervention group reported being in permanent housing at the 12 month follow-up interview (69% compared to 30%). Data was not reported for number of nights spent in shelter (63).
The results and quality assessments for residential treatment with case management vs usual services is summarized in Table 32. The complete GRADE evidence profile is shown in Appendix 8,  *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval 1.
Risk of attrition bias, reporting bias in one study. Inadequate reporting of methods in both studies.

What does the evidence say?
Residential treatment with case management compared to usual services: • May reduce the proportion of nights spent homeless (low certainty evidence).
• May increase the proportion of time spent in stable housing (low certainty evidence).
• May increase the number of participants who are in stable housing after one year (low certainty evidence).

Discussion
In this systematic review we aimed to summarize empirical research assessing the effect of housing programs and case management on improving housing stability and reducing homelessness for individuals who are homeless, or are at-risk of becoming homeless. We included 43 randomized controlled trials with a total of approximately 10,570 participants. The majority of the studies included adult participants with mental illness and/or substance abuse. All of the studies were assessed as having high risk of bias. Five main groups of interventions were identified: case management, abstinence-contingent housing, non-abstinence-contingent housing, housing vouchers, and residential treatment. The interventions were compared to usual services or another intervention. In practice, this means that all participants received or had access to some type of service.
Within these groups, a total of 28 comparisons assessed housing stability and/or homelessness. In addition, many of the included studies also addressed secondary outcomes such as employment, physical or mental health, quality of life, social support networks, substance abuse and criminal activity.
Overall, the findings suggest that case management and housing programs are consistently more effective than usual services in reducing homelessness and increasing the amount of time spent in stable housing. It is difficult to conclude whether interventions which combine housing with case management are more effective than case management only since only one study included that comparison and this evidence was assessed as having very low certainty.

Discussion of main results
We included 24 studies that evaluated the effect of case management on housing stability and/or homelessness. Eligibility criteria in the majority of the studies included homeless adults or those at-risk of becoming homeless, with mental illness and/or substance abuse issues. Three studies included other populations (disadvantaged youth, recently released criminal offenders, and homeless adults with families). Case management is a broad term and includes an array of interventions. For the purpose of this review, we therefore categorized them into either high intensity, where the intervention was described as assertive community treatment or intensive case management, or low intensity, where the intensity was not specified, or where case managers met with participants less than weekly. These interventions were compared with either usual services, 85 The Campbell Collaboration | www.campbellcollaboration.org another type of case management (of varying intensity), or an intervention that included neither a case management nor a housing component (for example motivational enhancement therapy). Importantly, even comparison group participants who received usual services were offered some type of service, support or treatment. This means that all interventions were, in reality, compared to an active comparison group to some degree.

Case management
High intensity case management probably reduces by almost one-third the number of individuals with mental illness and/or substance abuse problems who report being homeless, and increases by about 25% the number in stable housing 12-18 months after services are initiated compared to individuals who are offered usual services. It probably leads to little or no difference in the number of people (with mental illness and/or substance abuse, or recently released criminal offenders) who experience some homelessness during a two year period. Furthermore, high intensity case management may lead to a lower mean number of days spent homeless compared to usual services for both adults with mental illness and/or substance abuse problems and homeless adults with families. Taken together these findings suggest that although individuals who receive high intensity case management are probably just as likely to experience some homelessness, overall it may be fewer days total. For this reason, at any given point in time (e.g. follow-up interview), individuals who receive high intensity case management are less likely to be homeless and more likely to be in stable housing, compared to individuals who are offered usual services.
When compared to low intensity case management, high intensity case management may lead to little or no difference in the number of days spent in stable housing or the number of participants who experience some homelessness.
For many of the outcomes, both the quantity and quality of available evidence was too limited to draw conclusions. Many of these outcomes are related to mean number of days in stable housing or homeless, longest residence, number of moves, number of people who report not moving, and the number of days in better or worse housing.
In summary, it appears as though high intensity case management is better than usual services, but not better than low intensity case management in improving housing stability and reducing homelessness for adults with mental illness and/or substance abuse problems and homeless adults with families. This is perhaps not surprising given the variation in how the case management interventions are designed and implemented. It may indicate that in practice there is not much difference with respect to intensity, for example, between high intensity (ACT and ICM) and low intensity case management interventions. Alternatively, it may suggest that having at least one individual (case manager) guiding and supporting a participant through the number of disjointed services may be more important than the degree of intensity of the intervention.
For the two comparisons which included young people or youth, the results showed that case management (high or low) compared to usual services or another intervention with no housing or case management component may lead to little or no difference in number of days spent homeless, 86 The Campbell Collaboration | www.campbellcollaboration.org the number who were homeless at follow-up or the number of moves experienced during a 12month period. These results differ slightly from the comparisons which only included adults. Chamberlain and MacKenzie (2004) described the stages which youth go through before they are identified as homeless and argued for prevention and interventions which target these stages: 1) atrisk as identified by school counsellors, 2) runaways, 3) no longer belonging to the family, and 4) transition to chronicity where there are longer periods of homelessness (84). Chamberlain and MacKenzie (2004) argued that in the later stages, interventions with community placement components are necessary. Participants from both of the included studies (comparing high or low intensity case management to usual services or another intervention with no housing or case management component) included youth in the last stage (homeless or history of homelessness). In one study, the case management condition did not seem to include the community placement component, while in the other study, the comparison groups appeared to include equal or greater community placement components (CRA and MET). This could explain why there were no differences between the groups on housing stability or homelessness for this particular population. Alternatively, youth are often considered much more vulnerable and may just require more intensive case management services than even the high intensity case management models such as ICM and ACT which are intended for adults, currently provide.
Critical time intervention (CTI) may be more effective than usual services at improving housing stability and reducing homelessness for adults with mental illness. Even though individuals who receive CTI may be just as likely to experience some homelessness as individuals who receive usual services, they may spend fewer days homeless in total, and take half as long to leave shelter for stable or community housing.
Our findings are largely consistent with those from other reviews of case management for homeless populations (18, 20, 28). Coldwell and Bender (2007) also found that assertive community treatment reduced homelessness among populations with severe mental illness (28). Nelson and colleagues (2007) also found ACT and ICM to be superior to standard care for achieving housing stability among individuals with mental illness (20). Most recently de Vet and colleagues concluded that case management has a positive effect on homeless populations compared to standard care (18). Slesnick and colleagues (2009) summarized the research on youth homelessness and also concluded that comprehensive interventions that address youth and families, rather than singleissue interventions (such as case management), may be more successful with this particular population (30). This review included a wide variety of study designs and provided an overview of the studies rather than a synthesis of results.
However, our review differs from previous systematic reviews in five main ways: 1) we have included only randomized controlled trials, which are considered the best method for examining the effectiveness of an intervention; 2) we have only included studies which follow participants for at least one year; 3) we have grouped interventions according to low and high intensity and thus we have results for a larger group of interventions rather than individual models of case management (e.g. ACT, ICM); 4) we have pooled the results (continuous and dichotomous separately) where possible which has allowed us to look at the evidence across studies and not conclude based on 87 The Campbell Collaboration | www.campbellcollaboration.org small sample sizes from individual studies, and; 5) we have applied GRADE to the outcomes and thus provided a more concrete indication of our certainty in the evidence.

Abstinence-contingent housing
Abstinence-contingent housing combined with day treatment may reduce the number of days spent homeless when compared with usual services; however, we are uncertain of its effects on housing stability and homelessness when compared with other interventions due to very low certainty evidence. Furthermore, we are uncertain of the effects of abstinence-contingent housing with case management.

Non-abstinence-contingent housing
We identified two categories of non-abstinence-contingent housing: Housing First, and other programs that did not explicitly use the Housing First model. The Housing First model probably improves housing stability and reduces homelessness compared to usual services. There are no previous systematic reviews that we are aware of that have specifically looked at the effects of Housing First on housing and homelessness. The results from this review indicate 1) that Housing First probably reduces homelessness and increases the number of days in stable housing among adults with mental or chronic medical illness; and 2) may double the number of participants placed in permanent housing within two years.
We are uncertain of the effects of Housing First when compared with abstinence-contingent housing due to very low certainty evidence. However, there are no indications that Housing First is less effective in reducing homelessness or improving housing stability.
The results discussed here are from studies conducted in the USA and in Canada. The consistency of the above results, which include multiple settings with diverse social welfare, political and economic settings, supports the idea that Housing First can work in a variety of settings.
Non-abstinence contingent housing programs that did not explicitly employ the Housing First model may also reduce the amount of time spent homeless or living in shelters and increase the amount of time in stable housing compared to usual services. Furthermore, group homes where tenancy is not contingent on treatment adherence or sobriety may reduce the amount of time homeless compared to independent apartments with similar non-abstinence contingent tenancy.
However, when compared with abstinence-contingent housing (integrated housing), nonabstinence contingent housing may be less effective at reducing homelessness and improving housing stability.
We are uncertain of the effect of non-abstinence contingent housing combined with day treatment compared with day treatment only due to very low certainty evidence. 88 The Campbell Collaboration | www.campbellcollaboration.org

Housing vouchers
All of the included studies were conducted in the USA and thus used Section 8 Housing Vouchers provided by the Department of Housing and Urban Development. These housing vouchers combined with case management are probably more effective in reducing homelessness and improving the amount of time in stable housing than usual services or case management alone for adults with mental illness or HIV. Housing vouchers may help homeless families leave temporary shelters more quickly and stay out of shelters for longer periods of time.

Residential treatment with case management
Residential treatment with case management for adults with mental illness and/or substance abuse may be more effective at reducing the amount of time people spend homeless after leaving treatment, and increase both the amount of time spent in stable housing and the proportion of participants who are in stable housing one year after beginning treatment.

Completeness of the evidence
The identified studies include a fairly good representation of the typical populations which struggle with housing stability (adults with mental illness and/or substance abuse) as well as some relatively smaller portions of the homeless population (families, youth, recently released criminal offenders). The included studies also examined, altogether, all of the interventions which were identified in the protocol for the project. They were compared to both usual services and other interventions. As specified in the inclusion criteria, all of the studies addressed the primary outcomes (homelessness and housing stability) and many of the studies also examined secondary outcomes.
There are, however, three legitimate concerns regarding applicability of the review findings to other contexts. Firstly, usual services may differ substantially from context to context (e.g. between Denmark and the USA, or between states within the USA). Relatively better usual services in a given context may reduce the difference in outcomes between intervention and usual services groups. Secondly, there is a concern regarding the definition of homelessness. In some countries, "homeless" includes "literally homeless," or people with no shelter (living on the streets). In contexts where homelessness is defined more broadly (anyone in transitional or unstable housing) there may be less of a difference between intervention and control groups for some outcomes.

Quality of the evidence
Although all 43 of the included studies were randomized controlled trials, all studies with the exception of one were assessed as having high risk of bias. This high risk of bias is due to: risk of selection bias, particularly poor randomization (N=4) or poor allocation concealment procedures (N=4); performance bias (N=21); detection bias (N=12); attrition bias (N=15); or reporting bias 89 The Campbell Collaboration | www.campbellcollaboration.org (N=2). In 12 studies other risks of bias were also identified, including addition of new participants halfway through the study period without providing details regarding demographics or background, self-selection of participants during pre-treatment assessment period or discretionary approval of individuals' participation in the study by the implementing institutions, participants moving between intervention and control conditions, and treatment diffusion, introduction of new policies which resulted in media attention or impacted "usual services" during the study period, and varying degrees of treatment fidelity as discussed by the primary authors. However, the most common issue across studies was poor reporting of methods, including inadequate reporting of randomization, allocation and blinding methods. In many studies it was not possible to ascertain whether attempts were made to blind participants, personnel or outcome assessors to the assigned intervention condition. It can be assumed, due to the nature of the intervention, that blinding was neither possible nor attempted in most of these studies, and thus we often interpreted unclear reporting for these domains as high risk of bias. We attempted to assess risk of bias separately for subjective and objective outcomes due to the lack of or unclear blinding of participants and personnel, as performance bias is more likely to influence subjective outcomes than objective outcomes. However, there were very few objective outcomes included in the study. When number of days spent homeless or in different housing situations was reported, it was either explicitly indicated that these were self-report measures using an interview form, or the data collection methods were not described (i.e. no mention of use of administrative records) and we assumed self-report measures were employed. Some of the secondary outcomes reported in the individual studies used objective measures such as urine analysis; however, we have not graded evidence for any secondary outcomes.

Strengths and limitations of this review
This review has numerous strengths. Firstly, the findings of this review are based on a rigorous and systematic search of the published and grey literature. Furthermore, identification and selection of relevant studies and publications were carried out by at least two reviewers and based on a priori defined criteria. This was also the case for data extraction, appraisal of the risk of bias in the included studies and grading of the evidence for all outcomes. The published protocol is available at kunnskapssenteret.no. Secondly, we only included randomized controlled trials, thereby including evidence from only the most appropriate study design to answer this review of effectiveness. Thirdly, many of the included studies presented enough data on the difference between groups so that it was possible to statistically estimate the effect of case management or housing programs on housing stability and homelessness. Fourthly, by appraising the methodological quality of the included studies and grading the evidence, we are able to point out clear areas where future research can be improved in terms of design, conduct and reporting. Finally, by including both housing programs and case management interventions, we have provided a comprehensive overview of what is known about the effect of most types of interventions available to prevent or reduce homelessness among homeless or at-risk groups and a comparison of their relative effectiveness where possible. 90 The Campbell Collaboration | www.campbellcollaboration.org However, this review is not without limitations. Firstly, the complex nature of the interventions included in this review have three important consequences: 1) we may have missed relevant interventions in the literature search that were labelled as something else but included many or all of the same components of the included interventions; 2) we have grouped interventions together in an attempt to provide the end user with a more clear overview of types of interventions that work -this unavoidably leads to less detail regarding individual interventions, and; 3) the included interventions are likely to have varied greatly in how they were implemented, between study sites and across studies, even where they were reported as having followed a specific model (e.g. Housing First). We have not reported treatment fidelity for the included programs. Treatment fidelity was not systematically reported in the included studies, and was thus left out of our analysis. Secondly, due to archiving problems, we are unable to provide a complete list of reasons for exclusion for studies excluded after being read in full-text in the first search. Thirdly, for resource reasons, we have not attempted to synthesize, narratively or through meta-analysis, results for secondary outcomes. Finally, we did not extract data on, or include, cost-effectiveness data, which is important in making decisions on implementing such large social interventions, nor did we include qualitative research, which is used to examine participants' perceptions, preferences and/or experiences with interventions.

Conclusion
In this comprehensive systematic review of 43 randomized controlled trials, we aimed at determining the effect of interventions to improve residential stability and reduce homelessness. We found that housing programs and case management interventions appear to improve housing stability and reduce homelessness compared to usual services. There was no evidence that housing programs or case management resulted in poorer outcomes for homeless or at-risk individuals than usual services.

Research gaps
There is a great deal of research available on interventions to improve housing stability and reduce homelessness, as demonstrated by the large number of randomized controlled trials included in this review (and the large number of quasi-experimental studies excluded). However, the majority of the existing research has been judged to have high risk of bias, mostly due to poor reporting of methods, and lack of blinding of participants, personnel and outcome assessors. Although it is impossible to blind personnel and participants due to the nature of the interventions, the outcome assessors could be blinded. Furthermore, there has been no clear improvement in reporting between the year the first included study was published (1992) and 2015 (the most recent publication). Specifically, details are lacking regarding comparison group conditions, and the reporting of effect estimates within primary studies is inadequate.
Aside from a general need for better conducted and reported studies, there are specific gaps in the research: • Case management for specific sub-groups, specifically families and disadvantaged youth • Abstinence-contingent housing with case management or day treatment • Non-abstinence contingent housing, specifically different living arrangements (group vs independent living) • Housing First compared to interventions other than usual services (e.g. abstinence-contingent housing, case management only, housing vouchers) • All interventions from contexts other than the USA Department of Health and Human Services, editor.

Roles and responsibilities
Author1 was responsible for the writing of this report. Author 2 and Author 3 contributed to the process of including and excluding studies, critical appraisal, and commenting on the manuscript. Information Retrieval Specialists Ingvild Kirkehei and Lien Nguyen were responsible for the searches conducted in 2014 and 2016 respectively. We would like to acknowledge Sissel Johansen and Karianne Thune Hammerstrøm for their assistance in screening studies from the 2014 search.

Sources of support
Norwegian Institute of Public Health. This review was commissioned by the Norwegian State Housing Bank.

Declarations of interest
The authors have no vested interest in the outcomes of this review, nor any incentive to represent findings in a biased manner.

Plans for updating the review
Heather M. Munthe-Kaas will be responsible for updating this review as additional evidence and/or funding becomes available.

Appendices
Appendix 1: Glossary Housing offered where residents are expected to abstain from alcohol or drugs.

At-risk of Homelessness
People who are living in sub-standard, unstable or unsafe housing. This includes people who are "couch surfing," which means they are staying with family or friends, living in trailers, doubled or tripled up in small apartments or living in unsafe and unsanitary conditions (93).

Broker case management
A brief approach to case management. The case manager does not provide services, but rather attempts to help clients identify their own needs and broker supportive services (85).
Case management A collaborative process that assesses, plans, implements, coordinates, monitors, and evaluates the options and services required to meet an individual's health needs, using communication and available resources to promote quality, cost-effective outcomes (91).

Case Manager
A healthcare professional who is responsible for coordinating the care delivered to an assigned group of patients based on diagnosis or need. Other responsibilities include patient/family education, advocacy, delays management, and outcomes monitoring and management. Case managers work with people to get the healthcare and other community services they need, when they need them, and for the best value (91).

Caseload
The total number of patients followed by a case manager at any point in time (91).

Community reinforcement approach (CRA)
"CRA is an operant-based therapy with the goal to help individuals restructure their environment so that drug use or other maladaptive behaviors are no longer reinforced and other positive behaviors are reinforced… Therapists follow a standard set of core procedures… [which] include topics include (1) a functional analysis of using behaviors, (2) refusal skills training, and (3) relapse prevention (4) job skills, (5) social skills training including communication and problemsolving skills, (6) social and recreational counseling, (7) anger management and affect regulation" (76), p5.

Continuum of Care
The continuum of care matches ongoing needs of the individuals being served by the case management process with the appropriate level and type of health, medical, financial, legal and psychosocial care for services within a setting or across multiple settings (91).

Continuum of Care
Federal program stressing permanent solutions to homelessness (HUD)

Critical time intervention
Community-based case management in three phases of three months each. 1) Transition to community -case manager tries to identify needs and form connections. 2) Try out -where case manager and participants test out support system while trying to secure stable housing; 3) Transfer to carerefinements are made to support system to ensure long-term sustainability and case managers cut down on contact with participants (72).

Emergency housing
Short-term shelter for people in crisis. Some emergency shelters also provide meals and support services to the people who stay there (93).

Group Home
A home that is shared by a number of tenants who are generally expected to participate in shared living arrangements and activities. There is usually 24-hour support staff on site (93).

Housing First
Founded on the idea that housing is a basic right. The two core foundations of the program include psychiatric rehabilitation and consumer choice. Individuals are encouraged to define their own needs and goals. Housing is provided immediately by the program if the individual wishes, and there are no contingencies related to treatment or sobriety. The individual is also offered treatment, in the form of an adapted version of Assertive Community treatment (addition of a nurse practitioner to address physical health problems, and a housing specialist) (24).

Independent Living
A service delivery concept that encourages the maintenance of control over one's life based on the choice of acceptable options that minimize reliance on others performing everyday activities (91).
Intensity of Service An acuity of illness criteria based on the evaluation/treatment plan, interventions, and anticipated outcomes (91)

Intensive case management (ICM)
A thorough, long-term service to assist clients with serious mental illness (particularly those with psychiatric and functional disabilities and a history of not adhering to prescribed outpatient treatment) by establishing and maintaining linkages with community-based service providers. ICM typically provides referrals to treatment programs, maintains advocacy for clients, provides counseling and crisis intervention, and assists in a wide variety of other basic services (90).

Motivational Enhancement Therapy (MET)
An adaptation of motivational interviewing which includes feedback Motivational interviewing has four principles: "express accurate empathy, develop discrepancy, roll with resistance and support self-efficacy" (76), p5.

Non-abstinencecontingent housing (wet housing)
Housing where tenants are not expected to abstain from using alcohol and other drugs, and where entering a rehabilitation program is not a requirement. Tenants have access to recovery services and get to decide if and when they use these services. Wet housing programs follow a harm reduction philosophy. For more on harm reduction see below (93).

Permanent housing
Long-term housing with no maximum length of stay (93).

Private Market housing
Traditional rental housing that is run by private landlords rather than a housing program (93).

Quasiexperimental study design
Methods of allocating people to a trial that are not random, but were intended to produce similar groups when used to allocate participants. Quasi-random methods include: allocation by the person's date of birth, by the day of the week or month of the year, by a person's medical record number, or just allocating every alternate person. In practice, these methods of allocation are relatively easy to manipulate, introducing selection bias. See also random allocation, randomisation (92).

Randomized controlled trial
An experiment in which two or more interventions, possibly including a control intervention or no intervention, are compared by being randomly allocated to participants. In most trials one intervention is assigned to each individual but sometimes assignment is to defined groups of individuals (for example, in a household) or interventions are assigned within individuals (for example, in different orders or to different parts of the body) (92).

Section 8 Housing Vouchers
Housing 1. runaway behavior/ 2. homeless/ 3. homeless mentally ill/ 4. (evict* or homeless* or "housing excl*" or "living on the street*" or "residential stability" or "stable housing" or "street dwell*" or "Private dwell*" or "Improvised dwell*" or "Shelter dwell*" or "street liv*" or "Street life" or "street youth" or "street children" or "street people" or "marginally housed" or "precarious housing" or runaway* or "Run away from home" or "Running away" or "Ran away" or "Going missing" or "Bag lady" or Houseless* or Unhoused or "without a roof" or Roofless or "rough sleeper" or "rough sleepers" or "Rough sleeping" or Destitute* or "Skid row*" or "Street people" or "Street person*" or "Street youth*" or "Street child" or "Street children" or "Street life" or "Street living" or "Sleeping rough" or "sleep rough" or "rough sleep" or "emergency accommodation" or "temporary accommodation" or "Insecure accommodation" or "overcrowded accommodation" or "sleepers out").tw. 5. 1 or 2 or 3 or 4 6. ("Housing first" or "Pathways to Housing" or "Homeless Veterans Reintegration Program" or "Access to Community Care and Effective Services and Supports" or "Support* Housing Program" or "Housing and Urban Development Veterans Affairs Supported Housing program" or "HUD-VASH" or "Sober Transitional Housing and Employment Project" or "sober house placement*" or "Housing ladders" or "Staircase housing" or "low threshold housing" or "Critical Time Intervention").tw. 7. 5 or 6 8. (quasi-experimental or quasi-experiment or quasiexperiment or quasiexperimental or Propensity score or propensity scores or "control group" or "control groups" or "controlled group" or "controlled groups" or "treatment group" or "treatment groups" or "comparison group" or "comparison groups" or "wait-list" or "waiting list" or "wait-lists" or "waiting lists" or "intervention group" or "intervention groups" or "experimental group" or "experimental groups" or "matched control" or "matched groups" or "matched comparison" or "experimental trial" or "experimental design" or "experimental method" or "experimental methods" or "experimental study" or "experimental studies" or "experimental evaluation" or "experimental test" or "experimental tests" or "experimental testing" or "experimental assessment" or placebo or "assessment only" or treatment-as-usual or "services as usual" or "care as usual" or "usual treatment" or "usual service" or "usual services" or "usual care" or "standard treatment" or "standard treatments" or "standard service" or "standard services" or "standard care" or "traditional treatment" or "traditional service" or "traditional care" or "ordinary treatment" or "ordinary service" or "ordinary services" or "ordinary care" or "comparison sample" or propensitymatched or control sample or intervention sample or assigned randomly or randomly assigned or random* control*).tw. 9. treatment outcomes/ 10. group*.ab. 11. 9 and 10 12. quasi experimental methods/ 13. exp experimental design/ 14. clinical trials/ 15. placebo/ 16. random sampling/ 17. ("comparative testing" or "control groups" or "experimental groups" or "matched groups" or "quasiexperimental design").tw. 18. ("random assignment" or "random allocation" or "randomi?ed control*" or "randomi?ed trial" or "randomi?ed design" or "randomi?ed method" or "randomi?ed evaluation" or "randomi?ed test" or "randomi?ed assessment" ( AB(quasi-experimental OR quasi-experiment or quasiexperiment OR quasiexperimental OR Propensity score OR propensity scores OR "control group" OR "control groups" OR "controlled group" OR "controlled groups" OR "treatment group" OR "treatment groups" OR "comparison group" OR "comparison groups" OR "wait-list" OR "waiting list" OR "wait-lists" OR "waiting lists" OR "intervention group" OR "intervention groups" OR "experimental group" OR "experimental groups" OR "matched control" OR "matched groups" OR "matched comparison" OR "experimental trial" OR "experimental design" OR "experimental method" OR "experimental methods" OR "experimental study" OR "experimental studies" OR "experimental evaluation" OR "experimental test" OR "experimental tests" OR "experimental testing" OR "experimental assessment" OR placebo OR "assessment only" OR treatment-as-usual OR "services as usual" OR "care as usual" OR "usual treatment" OR "usual service" OR "usual services" OR "usual care" OR "standard treatment" OR "standard treatments" OR "standard service" OR "standard services" OR "standard care" OR "traditional treatment" OR "traditional service" OR "traditional care" OR "ordinary treatment" OR "ordinary service" OR "ordinary services" OR "ordinary care" OR "comparison sample" OR propensity-matched OR control sample OR intervention sample OR assigned randomly OR randomly assigned OR random* control*) ) OR ( TI(quasi-experimental OR quasi-experiment or quasiexperiment OR quasiexperimental OR Propensity score OR propensity scores OR "control group" OR "control groups" OR "controlled group" OR "controlled groups" OR "treatment group" OR "treatment groups" OR "comparison group" OR "comparison groups" OR "wait-list" OR "waiting list" OR "wait-lists" OR "waiting lists" OR "intervention group" OR "intervention groups" OR "experimental group" OR "experimental groups" OR "matched control" OR "matched groups" OR "matched comparison" OR "experimental trial" OR "experimental design" OR "experimental method" OR "experimental methods" OR "experimental study" OR "experimental studies" OR "experimental evaluation" OR "experimental test" OR "experimental tests" OR "experimental testing" OR "experimental assessment" OR placebo OR "assessment only" OR treatment-asusual OR "services as usual" OR "care as usual" OR "usual treatment" OR "usual service" OR "usual services" OR "usual care" OR "standard treatment" OR "standard treatments" OR "standard service" OR "standard services" OR "standard care" OR "traditional treatment" OR "traditional service" OR "traditional care" OR "ordinary treatment" OR "ordinary service" OR "ordinary services" OR "ordinary care" OR "comparison sample" OR propensity-matched OR control sample OR intervention sample OR assigned randomly OR randomly assigned OR random* control*) ) 6 (quasi-experimental OR quasi-experiment or quasiexperiment OR quasiexperimental OR Propensity score OR propensity scores OR "control group" OR "control groups" OR "controlled group" OR "controlled groups" OR "treatment group" OR "treatment groups" OR "comparison group" OR "comparison groups" OR "wait-list" OR "waiting list" OR "wait-lists" OR "waiting lists" OR "intervention group" OR "intervention groups" OR "experimental group" OR "experimental groups" OR "matched control" OR "matched groups" OR "matched comparison" OR "experimental trial" OR "experimental design" OR "experimental method" OR "experimental methods" OR "experimental study" OR "experimental studies" OR "experimental evaluation" OR "experimental test" OR "experimental tests" OR "experimental testing" OR "experimental assessment" OR placebo OR "assessment only" OR treatment-as-usual OR "services as usual" OR "care as usual" OR "usual treatment" OR "usual service" OR "usual services" OR "usual care" OR "standard treatment" OR "standard treatments" OR "standard service" OR "standard services" OR "standard care" OR "traditional treatment" OR "traditional service" OR "traditional care" OR "ordinary treatment" OR "ordinary service" OR "ordinary services" OR "ordinary care" OR "comparison sample" OR propensity-matched OR control sample OR intervention sample OR assigned randomly OR randomly assigned OR random* control*) 7 (MH "Quasi-Experimental Studies") or (MH "Nonequivalent Control Group") or (MH "Control Group") or (MH "Experimental Studies+") or (MH "Waiting Lists") or (MH "Matched-Pair Analysis") or (MH "Clinical Trials+") or (MH "Placebos") or (MH "Random Assignment") or (MH "Random Sample+") or (MH "Matched-Pair Analysis") or (MH "Case Control Studies") 8 (MH "Treatment Outcomes") and (AB group) 9 TI random assignment or TI random allocation or TI randomi?ed control* or TI randomi?ed trial or TI randomi?ed design or TI randomi?ed method or TI randomi?ed evaluation or TI randomi?ed test or TI randomi?ed assessment or TI randomi?ed or (AB random assignment or AB random allocation or AB randomi?ed control* or AB randomi?ed trial or AB randomi?ed design or AB randomi?ed method or AB randomi?ed evaluation or AB randomi?ed test or AB randomi?ed assessment) or (KW random assignment or KW random allocation or KW randomi?ed control* or KW randomi?ed trial or KW randomi?ed design or KW randomi?ed method or KW randomi?ed evaluation or KW randomi?ed test or KW randomi?ed assessment) 10 (MH "Clinical Trials+") 11 TX Controlled trial or TX Control trial 12 S5 OR S6 OR S7 OR S8 OR S9 OR S10 OR S11 13 S1 OR S2 OR S3 Limiters -Publication Type: Clinical Trial 14 S4 AND S12 15 S13 OR S14 Limiters 1. homeless persons/ or homeless youth/ 2. (evict* or homeless* or "housing excl*" or "living on the street*" or "residential stability" or "stable housing" or "street dwell*" or "Private dwell*" or "Improvised dwell*" or "Shelter dwell*" or "street liv*" or "Street life" or "street youth" or "street children" or "street people" or "marginally housed" or "precarious housing" or runaway* or "Run away from home" or "Running away" or "Ran away" or "Going missing" or "Bag lady" or Houseless* or Unhoused or "without a roof" or Roofless or "rough sleeper" or "rough sleepers" or "Rough sleeping" or Destitute* or "Skid row*" or "Street people" or "Street person*" or "Street youth*" or "Street child" or "Street children" or "Street life" or "Street living" or "Sleeping rough" or "sleep rough" or "rough sleep" or "emergency accommodation" or "temporary accommodation" or "Insecure accommodation" or "overcrowded accommodation" or "sleepers out").tw. explode all trees #2 evict* or homeless* or (housing next excl*) or ("living on the" next street*) or "residential stability" or "stable housing" or (street next dwell*) or (Private next dwell*) or (Improvised next dwell*) or (Shelter next dwell*) or (street next liv*) or "Street life" or "street youth" or "street children" or "street people" or "marginally housed" or "precarious housing" or runaway* or "Run away from home" or "Running away" or "Ran away" or "Going missing" or "Bag lady" or Houseless* or Unhoused or "without a roof" or Roofless or "rough sleeper" or "rough sleepers" or "Rough sleeping" or Destitute* or (Skid next row*) or "Street people" or (Street next person*) or (Street next youth*) or "Street child" or "Street children" or "Street life" or "Street living" or "Sleeping rough" or "sleep rough" or "rough sleep" or "emergency accommodation" or "temporary accommodation" or "Insecure accommodation" or "overcrowded accommodation" or "sleepers out" #3 "Housing first" or "Pathways to Housing" or "Homeless Veterans Reintegration Program" or "Access to Community Care and Effective Services and Supports" or "Supported Housing Program" or "Support Housing Program" or "Housing and Urban Development-Veterans Affairs Supported Housing program" or "HUD-VASH" or "Sober Transitional Housing and Employment Project" or "sober house placement*" or "Housing ladders" or "Staircase housing" or "low threshold housing" or "Critical Time Intervention" #4 #1 or #2 or #3 Publication Year from 2014 to 2016 Eric via ProQuest Dato: 20. januar 2016 Antall treff: 4 (SU.EXACT.EXPLODE("Homeless People") OR (evict* or homeless* or "housing excl*" or "living on the street*" or "residential stability" or "stable hou-sing" or "street dwell*" or "Private dwell*" or "Improvised dwell*" or "Shelter dwell*" or "street liv*" or "Street life" or "street youth" or "street children" or "street people" or "marginally housed" or "precarious housing" or "Housing first" or runaway* or "Run away from home" or "Running away" or "Ran away" or "Going missing" or "Bag lady" or Houseless* or Unhoused or "without a roof" or Roofless or "rough sleeper" or "rough sleepers" or "Rough sleeping" or Destitute* or "Skid row*" or "Street people" or "Street person*" or "Street youth*" or "Street child" or "Street children" or "Street life" or "Street living" or "Sleeping rough" or "sleep rough" or "rough sleep" or "emergency accommodation" or "temporary accommodation" or "Insecure accommodation" or "overcrowded accommodation" or "sleepers out" OR "Housing first" or "Pathways to Housing" or "Homeless Veterans Reintegration Program" or "Access to Community Care and Effective Services and Supports" or "Support* Housing Program" or "Housing and Urban Development-Veterans Affairs Supported Housing program" or "HUD-VASH" or "Sober Transitional Housing and Employment Project" or "sober house placement*" or "Housing ladders" or "Staircase housing" or "low threshold housing" or "Critical Time Intervention")) AND ((SU.EXACT("Comparative Testing") OR SU.EXACT("Control Groups") OR SU.EXACT("Matched Groups") OR SU.EXACT("Experimental Groups") OR SU.EXACT.EXPLODE("Quasiexperimental Design")) OR (quasi-experiment* or quasiexperiment* or "quasi experiment*" or "propensity scor*" or "control group*" or "controlled group*" or "treatment group*" or "comparison group*" or "wait-list*" or "waiting list*" or "intervention group*" or "experimental group*" or "matched control*" or "matched group*" or "matched comparison*" or "experimental trial*" or "experimental design*" or "experimental method*" or "experimental stud*" or "experimental evaluation*" or "experimental test*" or "experimental assessment*" or placebo or "assessment only" or "treatment as usual" or "services as usual" or "care as usual" or "usual treatment*" or "usual care" or "usual service" or "usual services" or "standard treatment" or "standard service*" or "standard care" or "traditional treatment" or "traditional service*" or "traditional care" or "ordinary treatment" or "ordinary service*" or "ordinary care" or "comparison sample" or propensity-matched or "control sample" or "intervention sample" or "assigned randomly" or "randomly assigned" or "random* control*") OR ab("treatment outcome" AND Group*) OR (ab(random*) OR ti((random* OR trial))) OR (("control trial") or ("controlled trial") or CCT)) Limits applied published 2014-2016
18612 18 ("random assignment" or "random allocation" or "randomi?ed control*" or "randomi?ed trial" or "randomi?ed design" or "randomi?ed method" or "randomi?ed evaluation" or "randomi?ed test" or "randomi?ed assessment" 5 ( AB(quasi-experimental OR quasi-experiment or quasiexperiment OR quasiexperimental OR Propensity score OR propensity scores OR "control group" OR "control groups" OR "controlled group" OR "controlled groups" OR "treatment group" OR "treatment groups" OR "comparison group" OR "comparison groups" OR "wait-list" OR "waiting list" OR "wait-lists" OR "waiting lists" OR "intervention group" OR "intervention groups" OR "experimental group" OR "experimental groups" OR "matched control" OR "matched groups" OR "matched comparison" OR "experimental trial" OR "experimental design" OR "experimental method" OR "experimental methods" OR "experimental study" OR "experimental studies" OR "experimental evaluation" OR "experimental test" OR "experimental tests" OR "experimental testing" OR "experimental assessment" OR placebo OR "assessment only" OR treatment-as-usual OR "services as usual" OR "care as usual" OR "usual treatment" OR "usual service" OR "usual services" OR "usual care" OR "standard treatment" OR "standard treatments" OR "standard service" OR "standard services" OR "standard care" OR "traditional treatment" OR "traditional service" OR "traditional care" OR "ordinary treatment" OR "ordinary service" OR "ordinary services" OR "ordinary care" OR "comparison sample" OR propensity-matched OR control sample OR intervention sample OR assigned randomly OR randomly assigned OR random* control*) ) OR ( TI(quasi-experimental OR quasi-experiment or quasiexperiment OR quasiexperimental OR Propensity score OR propensity scores OR "control group" OR "control groups" OR "controlled group" OR "controlled groups" OR "treatment group" OR "treatment groups" OR "comparison group" OR "comparison groups" OR "wait-list" OR "waiting list" OR "wait-lists" OR "waiting lists" OR "intervention group" OR "intervention groups" OR "experimental group" OR "experimental groups" OR "matched control" OR "matched groups" OR "matched comparison" OR "experimental trial" OR "experimental design" OR "experimental method" OR "experimental methods" OR "experimental study" OR "experimental studies" OR "experimental evaluation" OR "experimental test" OR "experimental tests" OR "experimental testing" OR "experimental assessment" OR 102,329 placebo OR "assessment only" OR treatment-as-usual OR "services as usual" OR "care as usual" OR "usual treatment" OR "usual service" OR "usual services" OR "usual care" OR "standard treatment" OR "standard treatments" OR "standard service" OR "standard services" OR "standard care" OR "traditional treatment" OR "traditional service" OR "traditional care" OR "ordinary treatment" OR "ordinary service" OR "ordinary services" OR "ordinary care" OR "comparison sample" OR propensity-matched OR control sample OR intervention sample OR assigned randomly OR randomly assigned OR random* control*) ) 6 (quasi-experimental OR quasi-experiment or quasiexperiment OR quasiexperimental OR Propensity score OR propensity scores OR "control group" OR "control groups" OR "controlled group" OR "controlled groups" OR "treatment group" OR "treatment groups" OR "comparison group" OR "comparison groups" OR "wait-list" OR "waiting list" OR "wait-lists" OR "waiting lists" OR "intervention group" OR "intervention groups" OR "experimental group" OR "experimental groups" OR "matched control" OR "matched groups" OR "matched comparison" OR "experimental trial" OR "experimental design" OR "experimental method" OR "experimental methods" OR "experimental study" OR "experimental studies" OR "experimental evaluation" OR "experimental test" OR "experimental tests" OR "experimental testing" OR "experimental assessment" OR placebo OR "assessment only" OR treatment-as-usual OR "services as usual" OR "care as usual" OR "usual treatment" OR "usual service" OR "usual services" OR "usual care" OR "standard treatment" OR "standard treatments" OR "standard service" OR "standard services" OR "standard care" OR "traditional treatment" OR "traditional service" OR "traditional care" OR "ordinary treatment" OR "ordinary service" OR "ordinary services" OR "ordinary care" OR "comparison sample" OR propensity-matched OR control sample OR intervention sample OR assigned randomly OR randomly assigned OR random* control*)  #3 ("Housing first" or "Pathways to Housing" or "Homeless Veterans Reintegration Program" or "Access to Community Care and Effective Services and Supports" or "Support* Housing Program" or "Housing and Urban Development-Veterans Affairs Supported Housing program" or "HUD-VASH" or "Sober Transitional Housing and Employment Project" or "sober house placement*" or "Housing ladders" or "Staircase housing" or "low threshold housing" or "Critical time intervention 8 Kommentar: Søk 7 er endret fra originalsøket da det ikke var mulig å få treffene til å stemme overens. Dette søket er noe videre, men det ser ikke ut til at det har bidratt til å gi treff til trefflisten.

S3
Searched for: ab(("Housing first" OR "Pathways to Housing" OR "Homeless Veterans Reintegration Program" OR "Access to Community Care and Effective Services" OR "Support* Housing Program" OR "Housing and Urban Development-Veterans Affairs Supported Housing program" OR HUD-VASH OR "Sober Transitional Housing" OR "sober house placement*" OR "Housing ladders" OR "Staircase housing" OR "low threshold housing" OR "Critical Time Intervention")) 75°

S4
Searched for: SU.EXACT.EXPLODE("Homelessness") OR ab((evict* OR homeless* OR "housing excl*" OR "living on the street*" OR "residential stability" OR "stable housing" OR "street dwell*" OR "Private dwell*" OR "Improvised dwell*" OR "Shelter dwell*" OR "street liv*" OR "Street life" OR "street youth" OR "street children" OR "street people" OR "marginally housed" OR "precarious housing" OR runaway* OR "Run away from home" OR "Running away" OR "Ran away" OR "Going missing" OR "Bag lady" OR Houseless* OR Unhoused OR "without a roof" OR Roofless OR "rough sleep*" OR Destitute* OR "Skid row*" OR "Street people" OR "Street person*" OR "Street youth*" OR "Street child" OR "Street children" OR "Street life" OR "Street living" OR "Sleep* rough" OR "rough sleep*" OR "emergency accommodation" OR "temporary accommodation" OR "Insecure accommodation" OR "overcrowded accommodation" OR "sleepers out")) OR ab(("Housing first" OR "Pathways to Housing" OR "Homeless Veterans Reintegration Program" OR "Access to Community Care and Effective Services" OR "Support* Housing Program" OR "Housing and Urban Development--Veterans Affairs Supported Housing program" OR HUD-VASH OR "Sober Transitional Housing" OR 8272* "sober house placement*" OR "Housing ladders" OR "Staircase housing" OR "low threshold housing" OR "Critical Time Intervention"))

S5
Searched for: ab(("quasi-experimental" OR quasi-experiment or quasiexperiment OR quasiexperimental OR "Propensity score" OR "propensity scores" OR "control group" OR "control groups" OR "controlled group" OR "controlled groups" OR "treatment group" OR "treatment groups" OR "comparison group" OR "comparison groups" OR "wait-list" OR "waiting list" OR "wait-lists" OR "waiting lists" OR "intervention group" OR "intervention groups" OR "experimental group" OR "experimental groups" OR "matched control" OR "matched groups" OR "matched comparison" OR "experimental trial" OR "experimental design" OR "experimental method" OR "experimental methods" OR "experimental study" OR "experimental studies" OR "experimental evaluation" OR "experimental test" OR "experimental tests" OR "experimental testing" OR "experimental assessment" OR placebo OR "assessment only" OR "treatment-as-usual" OR "services as usual" OR "care as usual" OR "usual treatment" OR "usual service" OR "usual services" OR "usual care" OR "standard treatment" OR "standard treatments" OR "standard service" OR "standard services" OR "standard care" OR "traditional treatment" OR "traditional service" OR "traditional care" OR "ordinary treatment" OR "ordinary service" Or "ordinary services" OR "ordinary care" OR "comparison sample" OR "propensity-matched" OR "control sample" OR "intervention sample" OR "assigned randomly" OR "randomly assigned" OR "random* control*")) 13720*

S9
Searched for: ab(("quasi-experimental" OR quasi-experiment OR quasiexperiment OR quasiexperimental OR "Propensity score" OR "propensity scores" OR "control group" OR "control groups" OR "controlled group" OR "controlled groups" OR "treatment group" OR "treatment groups" OR "comparison group" OR "comparison groups" OR "wait-list" OR "waiting list" OR "wait-lists" OR "waiting lists" OR "intervention group" OR "intervention groups" OR "experimental group" OR "experimental groups" OR "matched control" OR "matched groups" OR "matched comparison" OR "experimental trial" OR "experimental design" OR "experimental method" OR "experimental methods" OR "experimental study" OR "experimental studies" OR "experimental evaluation" OR "experimental test" OR "experimental tests" OR "experimental testing" OR "experimental assessment" OR placebo OR "assessment only" OR "treatment-as-usual" OR "services as usual" OR "care as usual" OR "usual treatment" OR "usual service" OR "usual services" OR "usual care" OR "standard treatment" OR "standard treatments" OR "standard service" OR "standard services" OR "standard care" OR "traditional treatment" OR "traditional service" OR "traditional care" OR "ordinary treatment" OR 15225* "ordinary service" OR "ordinary services" OR "ordinary care" OR "comparison sample" OR "propensity-matched" OR "control sample" OR "intervention sample" OR "assigned randomly" OR "randomly assigned" OR "random* control*")) OR ti(("random assignment" OR "random allocation" OR "randomi?ed control*" OR "randomi?ed trial" OR "randomi?ed design" OR "randomi?ed method" OR "randomi?ed evaluation" OR "randomi?ed test" OR "randomi?ed assessment" OR randomi?ed)) OR ab(("random assignment" OR "random allocation" OR "randomi?ed control*" OR "randomi?ed trial" OR "randomi?ed design" OR "randomi?ed method" OR "randomi?ed evaluation" OR "randomi?ed test" OR "randomi?ed assessment" OR randomi?ed)) OR ab(("Controlled trial" OR "Control trial" OR CCT)) S10 Searched for: (SU.EXACT.EXPLODE("Homelessness") OR ab((evict* OR homeless* OR "housing excl*" OR "living on the street*" OR "residential stability" OR "stable housing" OR "street dwell*" OR "Private dwell*" OR "Improvised dwell*" OR "Shelter dwell*" OR "street liv*" OR "Street life" OR "street youth" OR "street children" OR "street people" OR "marginally housed" OR "precarious housing" OR runaway* OR "Run away from home" OR "Running away" OR "Ran away" OR "Going missing" OR "Bag lady" OR Houseless* OR Unhoused OR "without a roof" OR Roofless OR "rough sleep*" OR Destitute* OR "Skid row*" OR "Street people" OR "Street person*" OR "Street youth*" OR "Street child" OR "Street children" OR "Street life" OR "Street living" OR "Sleep* rough" OR "rough sleep*" OR "emergency accommodation" OR "temporary accommodation" OR "Insecure accommodation" OR "overcrowded accommodation" OR "sleepers out")) OR ab(("Housing first" OR "Pathways to Housing" OR "Homeless Veterans Reintegration Program" OR "Access to Community Care and Effective Services" OR "Support* Housing Program" OR "Housing and Urban Development--Veterans Affairs Supported Housing program" OR HUD-VASH OR "Sober Transitional Housing" OR "sober house placement*" OR "Housing ladders" OR "Staircase housing" OR "low threshold housing" OR "Critical Time Intervention"))) AND (ab(("quasi-experimental" OR quasi-experiment OR quasiexperiment OR quasiexperimental OR "Propensity score" OR "propensity scores" OR "control group" OR "control groups" OR "controlled group" OR "controlled groups" OR "treatment group" OR "treatment groups" OR "comparison group" OR "comparison groups" OR "wait-list" OR "waiting list" OR "wait-lists" OR "waiting lists" OR "intervention group" OR "intervention groups" OR "experimental group" OR "experimental groups" OR "matched control" OR "matched groups" OR "matched comparison" OR "experimental trial" OR "experimental design" OR "experimental method" OR "experimental methods" OR "experimental study" OR "experimental studies" OR "experimental evaluation" OR "experimental test" OR "experimental tests" OR "experimental testing" OR "experimental assessment" OR placebo OR "assessment only" OR "treatment-as-usual" OR "services as usual" OR "care as usual" OR "usual treatment" OR "usual service" OR "usual services" OR "usual care" OR "standard treatment" OR "standard treatments" OR "standard service" OR "standard services" OR "standard care" OR "traditional treatment" OR "traditional service" OR "traditional care" OR "ordinary treatment" OR "ordinary service" OR "ordinary services" OR "ordinary care" OR "comparison sample" OR "propensity-matched" OR "control sample" OR "intervention sample" OR "assigned randomly" OR "randomly assigned" OR 201° "random* control*")) OR ti(("random assignment" OR "random allocation" OR "randomi?ed control*" OR "randomi?ed trial" OR "randomi?ed design" OR "randomi?ed method" OR "randomi?ed evaluation" OR "randomi?ed test" OR "randomi?ed assessment" OR randomi?ed)) OR ab(("random assignment" OR "random allocation" OR "randomi?ed control*" OR "randomi?ed trial" OR "randomi?ed design" OR "randomi?ed method" OR "randomi?ed evaluation" OR "randomi?ed test" OR "randomi?ed assessment" OR randomi?ed)) OR ab(("Controlled trial" OR "Control trial" OR CCT))) S11 Searched for: (SU.EXACT.EXPLODE("Homelessness") OR ab((evict* OR homeless* OR "housing excl*" OR "living on the street*" OR "residential stability" OR "stable housing" OR "street dwell*" OR "Private dwell*" OR "Improvised dwell*" OR "Shelter dwell*" OR "street liv*" OR "Street life" OR "street youth" OR "street children" OR "street people" OR "marginally housed" OR "precarious housing" OR runaway* OR "Run away from home" OR "Running away" OR "Ran away" OR "Going missing" OR "Bag lady" OR Houseless* OR Unhoused OR "without a roof" OR Roofless OR "rough sleep*" OR Destitute* OR "Skid row*" OR "Street people" OR "Street person*" OR "Street youth*" OR "Street child" OR "Street children" OR "Street life" OR "Street living" OR "Sleep* rough" OR "rough sleep*" OR "emergency accommodation" OR "temporary accommodation" OR "Insecure accommodation" OR "overcrowded accommodation" OR "sleepers out")) OR ab(("Housing first" OR "Pathways to Housing" OR "Homeless Veterans Reintegration Program" OR "Access to Community Care and Effective Services" OR "Support* Housing Program" OR "Housing and Urban Development--Veterans Affairs Supported Housing program" OR HUD-VASH OR "Sober Transitional Housing" OR "sober house placement*" OR "Housing ladders" OR "Staircase housing" OR "low threshold housing" OR "Critical Time Intervention"))) AND (ab(("quasi-experimental" OR quasi-experiment OR quasiexperiment OR quasiexperimental OR "Propensity score" OR "propensity scores" OR "control group" OR "control groups" OR "controlled group" OR "controlled groups" OR "treatment group" OR "treatment groups" OR "comparison group" OR "comparison groups" OR "wait-list" OR "waiting list" OR "wait-lists" OR "waiting lists" OR "intervention group" OR "intervention groups" OR "experimental group" OR "experimental groups" OR "matched control" OR "matched groups" OR "matched comparison" OR "experimental trial" OR "experimental design" OR "experimental method" OR "experimental methods" OR "experimental study" OR "experimental studies" OR "experimental evaluation" OR "experimental test" OR "experimental tests" OR "experimental testing" OR "experimental assessment" OR placebo OR "assessment only" OR "treatment-as-usual" OR "services as usual" OR "care as usual" OR "usual treatment" OR "usual service" OR "usual services" OR "usual care" OR "standard treatment" OR "standard treatments" OR "standard service" OR "standard services" OR "standard care" OR "traditional treatment" OR "traditional service" OR "traditional care" OR "ordinary treatment" OR "ordinary service" OR "ordinary services" OR "ordinary care" OR "comparison sample" OR "propensity-matched" OR "control sample" OR "intervention sample" OR "assigned randomly" OR "randomly assigned" OR "random* control*")) OR ti(("random assignment" OR "random allocation" OR "randomi?ed control*" OR "randomi?ed trial" OR "randomi?ed design" OR "randomi?ed method" OR "randomi?ed evaluation" OR "randomi?ed test" OR "randomi?ed 41° assessment" OR randomi?ed)) OR ab(("random assignment" OR "random allocation" OR "randomi?ed control*" OR "randomi?ed trial" OR "randomi?ed design" OR "randomi?ed method" OR "randomi?ed evaluation" OR "randomi?ed test" OR "randomi?ed assessment" OR randomi?ed)) OR ab(("Controlled trial" OR "Control trial" OR CCT))) AND yr ( TOPIC: (evict* or homeless* or "housing excl*" or "living on the street*" or "residential stability" or "stable hou-sing" or "street dwell*" or "Private dwell*" or "Im-provised dwell*" or "Shelter dwell*" or "street liv*" or "Street life" or "street youth" or "street children" or "street people" or "marginally housed" or "precarious housing" or "Housing first" or runaway* or "Run away from home" or "Running away" or "Ran away" or "Going missing" or "Bag lady" or Houseless* or Unhoused or "without a roof" or Roofless or "rough sleeper" or "rough sleepers" or "Rough sleeping" or Destitute* or "Skid row*" or "Street people" or "Street person*" or "Street youth*" or "Street child" or "Street children" or "Street life" or "Street living" or "Sleeping rough" or "sleep rough" or "rough sleep" or "emergency accommodation" or "temporary accommodation" or "Insecure accommodation" or "overcrowded accommodation" or "sleepers out") Timespan=All years TITLE: (evict* or homeless* or "housing excl*" or "living on the street*" or "residential stability" or "stable hou-sing" or "street dwell*" or "Private dwell*" or "Im-provised dwell*" or "Shelter dwell*" or "street liv*" or "Street life" or "street youth" or "street children" or "street people" or "marginally housed" or "precarious housing" or "Housing first" or runaway* or "Run away from home" or "Running away" or "Ran away" or "Going missing" or "Bag lady" or Houseless* or Unhoused or "without a roof" or Roofless or "rough sleeper" or "rough sleepers" or "Rough sleeping" or Destitute* or "Skid row*" or "Street people" or "Street person*" or "Street youth*" or "Street child" or "Street children" or "Street life" or "Street living" or "Sleeping rough" or "sleep rough" or "rough sleep" or "emergency accommodation" or "temporary accommodation" or "Insecure accommodation" or "overcrowded accommodation" or "sleepers out") Timespan=All years Search language=Auto # 5 264 TOPIC: ("Housing first" or "Pathways to Housing" or "Homeless Veterans Reintegration Program" or "Access to Community Care and Effective Services and Supports" or "Support* Housing Program" or "Housing and Urban Development-Veterans Affairs Supported Housing program" or "HUD-VASH" or "Sober Transitional Housing and Employment Project" or "sober house placement*" or "Housing ladders" or "Staircase housing" or "low threshold housing" or "Critical Time Intervention") Timespan=All years Search language=Auto # 6 124 TITLE: ("Housing first" or "Pathways to Housing" or "Homeless Veterans Reintegration Program" or "Access to Community Care and Effective Services and Supports" or "Support* Housing Program" or "Housing and Urban DevelopmentVeterans Affairs Supported Housing program" or "HUD-VASH" or "Sober Transitional Housing and Employment Project" or "sober house placement*" or "Housing ladders" or "Staircase housing" or "low threshold housing" or "Critical Time Intervention") TOPIC: (quasi-experiment* or quasiexperiment* or "quasi experiment*" or "propensity scor*" or "control group*" or "controlled group*" or "treatment group*" or "comparison group*" or "wait-list*" or "waiting list*" or "intervention group*" or "experimental group*" or "matched control*" or "matched group*" or "matched comparison*" or "experimental trial*" or "experimental design*" or "experimental method*" or "experimental stud*" or "experimental evaluation*" or "experimental test*" or "experimental assessment*" or placebo or "assessment only" or "treatment as usual" or "services as usual" or "care as usual" or "usual treatment*" or "usual care" or "usual service" or "usual services" or "standard treatment" or "standard service*" or "standard care" or "traditional treatment" or "traditional service*" or "traditional care" or "ordinary treatment" or "ordinary service*" or "ordinary care" or "comparison sample" or propensity-matched or "control sample" or "intervention sample" or "assigned randomly" or "randomly assigned" or "random* control*") OR TITLE:(quasi-experiment* or quasiexperiment* or "quasi experiment*" or "propensity scor*" or "control group*" or "controlled group*" or "treatment group*" or "comparison group*" or "wait-list*" or "waiting list*" or "intervention group*" or "experimental group*" or "matched control*" or "matched group*" or "matched comparison*" or "experimental trial*" or "experimental design*" or "experimental method*" or "experimental stud*" or "experimental evaluation*" or "experimental test*" or "experimental assessment*" or placebo or "assessment only" or "treatment as usual" or "services as usual" or "care as usual" or "usual treatment*" or "usual care" or "usual service" or "usual services" or "standard treatment" or "standard service*" or "standard care" or "traditional treatment" or "traditional service*" or "traditional care" or "ordinary treatment" or "ordinary service*" or "ordinary care" or "comparison sample" or propensity-matched or "control sample" or "intervention sample" or "assigned randomly" or "randomly assigned" or "random* control*") Timespan=All years Search language=Auto # 12 Approximately 997,570 TOPIC: ("random assignment" or "random allocation" or "randomi?ed control*" or "randomi?ed trial" or "randomi?ed design" or "randomi?ed method" or "randomi?ed evaluation" or "randomi?ed test" or "randomi?ed assessment") OR TOPIC: (control trial or controlled trial or CCT) OR TITLE: (control trial or controlled trial or CCT) OR TITLE: ("random assignment" or "random allocation" or "randomi?ed control*" or "randomi?ed trial" or "randomi?ed design" or "randomi?ed method" or "randomi?ed evaluation" or "randomi?ed test" or "randomi?ed assessment") 1. DE "homelessness" or "homeless adolescent girls" or "homeless boys" or "homeless children" or "homeless elderly people" or "homeless families" or "homeless men" or "homeless mentally ill men" or "homeless mentally ill people" or "homeless mentally ill women" or "homeless mentally ill young people" or "homeless mothers" or "homeless older people" or "homeless people" or "homeless pregnant women" or "homeless women" or "homeless young men" or "homeless young people" or "homeless young women" 1829 2. KW evict* or homeless* or "housing excl*" or "living on the street*" or "residential stability" or "stable housing" or "street dwell*" or "Private dwell*" or "Improvised dwell*" or "Shelter dwell*" or "street liv*" or "Street life" or "street youth" or "street children" or "street people" or "marginally housed" or "precarious housing" or "Housing first" or runaway* or "Run away from home" or "Running away" or "Ran away" or "Going missing" or "Bag lady" or Houseless* or Unhoused or "without a roof" or Roofless or "rough sleeper" or "rough sleepers" or "Rough sleeping" or Destitute* or "Skid row*" or "Street people" OR "Street person*" OR "Street youth*" OR "Street child" OR "Street children" OR "Street life" OR "Street living" or "Sleeping rough" or "sleep rough" or "rough sleep" or "emergency accommodation" OR "temporary accommodation" or "Insecure accommodation" OR "overcrowded accommodation" or "sleepers out" 3. KW "Housing first" OR "Pathways to Housing" OR "Homeless Veterans Reintegration Program" OR "Access to Community Care and Effective Services and Supports" OR "Support* Housing Program" OR "Housing and Urban Development-Veterans Affairs Supported Housing program" OR "HUD-VASH" OR "Sober Transitional Housing and Employment Project" OR "sober house placement*" OR "Housing ladders" OR "Staircase housing" OR "low threshold housing" OR "Critical Time Intervention" 21 4. 1 or 2 or 3 3157 5. DE ("control groups" or "experimental treatment" or "placebos" or "propensity" or "random sampling" or "random testing" or "randomization" or "samples" or "waiting lists") 505 6. FT(AB) "treatment outcome" near group 22 7. KW KW=(quasi-experiment* or quasiexperiment* or (quasi experiment*)) or KW=((propensity scor*) or (control group*) or (controlled group*)) or KW=((treatment group*) or (comparison group*) or wait-list*) or KW=((waiting list*) or (intervention group*) or (experimental group*)) or KW=((matched control*) or (matched group*) or (matched comparison*)) or KW=((experimental trial*) or (experimental design*) or (experimental method*)) or KW=((experimental stud*) or (experimental evaluation*) or (experimental test*)) or KW=((experimental assessment*) or placebo or (assessment only)) or KW=((treatment as usual) or (services as usual) or (care as usual)) or KW=((usual treatment*) or (usual care) or (usual service)) or KW=((usual services) or (standard treatment) or (standard service*)) or KW=((standard care) or (traditional treatment) or (traditional service*)) or KW=((traditional care) or (ordinary treatment) or (ordinary service*)) or KW=((ordinary care) or (comparison sample) or propensity-matched) or KW=((control sample) or (intervention sample) or (assigned randomly)) or KW=((randomly assigned) or (random* control*)) 15685 8. 5 or 6 or 7 15848 9.
KW=(("random assignment") or ("random allocation") or ("randomi?ed control*")) or KW=(("randomi?ed trial") or ("randomi?ed design") or ("randomi?ed method")) or KW=(("randomi?ed evaluation") or ("randomi?ed test") or ("randomi?ed assessment"))  (quasi-experimental OR quasi-experiment or quasiexperiment OR quasiexperimental OR Propensity score OR propensity scores OR "control group" OR "control groups" OR "controlled group" OR "controlled groups" OR "treatment group" OR "treatment groups" OR "comparison group" OR "comparison groups" OR "wait-list" OR "waiting list" OR "wait-lists" OR "waiting lists" OR "intervention group" OR "intervention groups" OR "experimental group" OR "experimental groups" OR "matched control" OR "matched groups" OR "matched comparison" OR "experimental trial" OR "experimental design" OR "experimental method" OR "experimental methods" OR "experimental study" OR "experimental studies" OR "experimental evaluation" OR "experimental test" OR "experimental tests" OR "experimental testing" OR "experimental assessment" OR placebo OR "assessment only" OR treatment-as-usual OR "services as usual" OR "care as usual" OR "usual treatment" OR "usual service" OR "usual services" OR "usual care" OR "standard treatment" OR "standard treatments" OR "standard service" OR "standard services" OR "standard care" OR "traditional treatment" OR "traditional service" OR "traditional care" OR "ordinary treatment" OR "ordinary service" OR "ordinary services" OR "ordinary care" OR "comparison sample" OR propensity-matched OR control sample OR intervention sample OR assigned randomly OR randomly assigned OR random* control*) 6.
(MH "Treatment Outcomes") and (AB group) "Housing first" OR "Pathways to Housing" OR "Homeless Veterans Reintegration Program" OR "Access to Community Care and Effective Services and Supports" OR "Support* Housing Program" OR "Housing and Urban Development-Veterans Affairs Supported Housing program" OR "HUD-VASH" OR "Sober Transitional Housing and Employment Project" OR "sober house placement*" OR "Housing ladders" OR "Staircase housing" OR "low threshold housing" OR "Critical time intervention" KW evict* or homeless* or "housing excl*" or "living on the street*" or "residential stability" or "stable hou-sing" or "street dwell*" or "Private dwell*" or "Im-provised dwell*" or "Shelter dwell*" or "street liv*" or "Street life" or "street youth" or "street children" or "street people" or "marginally housed" or "precarious housing" or "Housing first" or runaway* or "Run away from home" or "Running away" or "Ran away" or "Going missing" or "Bag lady" or Houseless* or Unhoused or "without a roof" or Roofless or "rough sleeper" or "rough sleepers" or "Rough sleeping" or Destitute* or "Skid row*" or "Street people" or "Street person*" or "Street youth*" or "Street child" or "Street children" or "Street life" or "Street living" or "Sleeping rough" or "sleep rough" or "rough sleep" or "emergency accommodation" or "temporary accommodation" or "Insecure accommodation" or "overcrowded accommodation" or "sleepers out" 2606 Intervention 3. KW "Housing first" or "Pathways to Housing" or "Homeless Veterans Reintegration Program" or "Access to Community Care and Effective Services and Supports" or "Support* Housing Program" or "Housing and Urban Development-Veterans Affairs Supported Housing program" or "HUD-VASH" or "Sober Transitional Housing and Employment Project" or "sober house placement*" or 6 "Housing ladders" or "Staircase housing" or "low threshold housing" or "Critical Time Intervention"

. Low intensity case management compared to usual services -Secondary outcomes
In one study (64) participants in the intervention group reported slightly more days in employment than the control group, but this difference was not significant (no numbers reported9. There was also no difference in psychiatric and social care needs, quality of life, social behaviour, or deviant behaviour between the two groups at the 14 month follow-up. In the other study (26) sosin participants in the intervention group reported 2.5 days less alcohol and drug consumption between baseline and 12 month follow-up (statistically significant). No data was reported for the control group.   The longitudinal difference between groups was not statistically significant across all time points (p=.504).   Table X in Appendix XX.

Study
Another study (43) also reported quality of life outcomes using the Aids Clinical Trial Group SF21 instrument. Results show that participants in the Housing First group reported slightly better physical functioning (MD=53.6 (95% CI 49.2 to 60.0)) than the control group (MD=52.2 (95% CI 46.9 to 57.4)) but that this was not significant (p=0.68). Participants in the Housing First group also reported slightly better mental health (M=57.0 (95% CI 52.8 to 61.3)) than the control group (M=54 (95% CI 49.1 to 58.9) but that this was not significant (p=0.35). There were no significant difference between the groups on criminal arrests or number of days in jail, but there were significant differences on number of convictions and days in prison in favour of the treatment group (p<0.10).     Appendix 6: Risk of bias in included studies

Participants Eligibility:
At least 18 years of age, fluent in English or Spanish, without stable housing during the 30 days prior to hospitalization, were not the guardian of minor children needing housing, and had at least one of 15 specified chronic medical illnesses documented in the medical record (hypertension or diabetes requiring medication, thromboembolic disease, renal failure, cirrhosis, congestive heart failure, myocardial infarction, atrial or ventricular arrhythmias, seizures within the past year or requiring medication for control, asthma or emphysema requiring at least 1 ER visit or hospitalization in the past 3 years, cancer, gastrointestinal tract bleeding (other than from peptic ulcer disease), chronic pancreatitis , HIV -chosen for the increased mortality risk they pose for homeless). Patients were ineligible if their hospital physician found them incapable of self-care upon hospital discharge No stat sig diff bw populations at baseline

Interventions
Case management: from on-site intervention social worker (provision of transitional housing at respite care centres, subsequent placement in stable housing, and case management) CM provided on-site at primary study sites, respite care facilities and stable housing cites. Conditional tenancy: not reported Housing provision: Housing first model -options provided by 10 agencies offering group or single living. Housing decisions based on availability, sex, sobriety, HIV status and geographic preference. Segregation: not reported Case management intensity: participants had contact with case managers at least biweekly. Case manager had weekly team meetings to coordinate the housing, social service and medical care needs Usual services: referred back to original hospital social worker, usual discharge planning services with no continued relationship after discharge. Typically provided transportation to an overnight shelter. People with HIV had access to case management after discharge through another program, others had access to general case management services. access to respite/stable housing was unaffected by participation in the study.  Drop-in centers (DI) and aftercare services (AC) DI-centers provide informal meeting places to experience fellowship, food, and recreation. Less demanding expectations than most day treatment programs. Clients are not "admitted" or "discharged", they are not required to participate in specific groups, to be actively involved in rehabilitation, or even to attend regularly. The DI-centers offer a range of social and recreational opportunities, have self-help ethos in which clients play a major role in club decision-making. Clients-staff ratios are high, but with no requirements for frequent contacts. The DI-center, a readily accessible, lowexpectation drop-in program, was conducted at the agency's main location. It had an average daily attendance of over 50 clients during the study period. The program operated during late afternoon and evening hours and on weekends, with several professional staff on site at all times when the program was open. Staff responsibilities were primarily to facilitate group activities, intervene in the case of major disruptions and crisis, converse with clients, and make referrals if necessary. The DI-center was staffed by a team of five paid workers, supplemented by numerous volunteers and trainees. The full-time coordinator was a highly experienced master's-level social worker. The remaining four positions (constituting two fulltime equivalents) were filled by a master's-level social worker with several year's of experience; a bachelor's-level artist who had also worked for many years as an inpatient psychiatric aide; an advanced graduate student in clinical psychology who had worked in the field for several years; and a bachelor's-level schoolteacher, active in the local chapter of the Alliance for the Mentally Ill. The program was not closely connected with a housing program.

Interventions Case management services with Occupational Therapist consultant (CM-OT)
-Occupational therapists were added to regular case management to stabilize or improve housing status and achieve client goal attainment.
-OT consultant used Canadian Occupational Performance measure (COPM) to provide each client with the opportunity to identify personally-meaningful goals for case management intervention.
-All clients received indepth evaluation by OT consultant -assessing cognitive functioning -OT consultant and client collaborated to determine and prioritize treatment goals.
-Experiemental group considered to receive regular on-going contact with the OT consultant both through case manager and directly in groups, individual meetings and home-based services.
-In order to address the treatment goals the clients identified during the evaluation process, the OT consultant developed and facilitated weekly activitiy groups and cshared client pgress and relevant client-group observatrions with case managers during weekly staff meetings.
-Group topics included diabetes education, life skills management,e xercise, relaxation, crafts, gardening and therapeutic horseback riding. Additionally the OT consultant modified the grocery shopping outing which had consisted of dropping the clients off at the entrance of the store and waiting for them to complete their purchases before returning them to the drop in center. The outing developed into agroup format which included assisting the clients in preparing their lists prior to the trip, teaching money management skills and techniques (use of coupons and newpaper inserts of weekly sales) and accompanying them throughout the store to provided needed cues or assistance to complete the shopping task. Conditionality of tenancy: NA Housing provision: NA Segregation: NA Case management intensity: seen once weekly for medication monitoring and money management Case management services with traditional non-Occupational Therapist (CM-TNOT) -All clients received indepth evaluation by OT consultant -assessing cognitive functioning -OT consultant and client collaborated to determine and prioritize treatment goals.
-Received traditional non-OT case management services with minimal contact from the OT consultant.
-Run by private community mental health center under collaborative agency partnership between mental health agency and homeless center. Community support program relied on case management services in which clients were generally seen once weekly for medication monitoring and money management by a paraprofessional case manager, most of whom were recent college graduates with limited work experience in mental health or any other field. Education ranged from GED to masters in social work and experience as case manager ranged from less than one month to more than 8 years. None of case managers were licensed or certified professionals in nursing, social work and none had formal education or certification in case management.
-High caseloads and frequent staff turnover -Case managers generally functioned as primary therapists for the client addressing basic needs money management, and safety.
-Case managers were able to bill for either providing services to clients or teaching them needed skills, but because state funding allowed for a higher reimbursement rate for providing services rather than teaching skills, case managers were generally encouraged to probide services (e.g. drive them to appointments instead of team them how to use public transportation) -Lack of rehabilitative approach.

Interventions Consumer staffed Assertive Community Treatment (CACT) or Assertive Community Treatment (ACT)
Staff were hired, trained, and supervised by a local consumer-run mental health agency, which also administratively operated the two programs. Each team consisted of four full-time and one part-time case manager, one of whom was the team leader. Staff members on the consumer-staffed team were self-identified mental health consumers with a DSM-III-R axis I diagnosis. Over the life of the project, the majority of the staff on this team had a diagnosis of bipolar disorder (50 percent); other diagnoses included major depression, schizoaffective disorder, and cyclothymia. Most members of the consumer-staffed team held a bachelor's degree. The consumer-staffed team had on average more previous experience in the mental health field (8.6 years, compared with four years). No indication of any deviation from the original ATC-model regarding the second team. Conditionality of tenancy: no direct information but non-conditionality is indicated ...a comprehensive array of services for meeting client needs; supported housing based on consumers choice.
Housing provision: no specific information Segregation: no information Clients were expected to take as strong a role as they were capable of in addressing their problems. Generic treatment program goals: stabilize client's financial condition and housing status, encourage substance use reduction. Conditionality of tenancy: no specific information regarding conditionality of housing, yet provision of the service was not conditional on client behavior and there was no requirement that clients maintained sobriety in order to continue in the program.
Housing provision: no specific information, yet In practice, a large portion of the case manager's time was spent in acquiring housing for clients, and an even larger portion was spent in helping maintaining them in housing once it was arranged. Segregation: no specific information Case management intensity: medium, case load 1:15, frequency and duration of contacts according to clients needs and capacities Usual Care No information, but control subjects were free to seek treatment from other sources in any way they wished, and some did. Participants Eligibility: Major psychotic disorder (schizophrenia, schizoaffective disorder, bipolar disorder, or major depression with psychotic features); had an active substance use disorder (abuse or dependence on alcohol or other drugs within the past 6 months); had high service use in the past two years (two or more of the following: psychiatric hospitalizations, stays in a psychiatric crisis or respite program, emergency department visits, or incarcerations); were homeless or unstably housed; had poor independent living skills; did not have any pending legal charges, medical conditions, or mental retardation that would preclude participation; were scheduled for discharge to community living if they were an inpatient; and were willing to provide written informed consent. Participants shelters, on the streets, and in institutional settings such as hospitals, detoxification centers, or jails, as well as the housing status at the end of the follow-up period. These data were compiled even for study participants who left project-sponsored housing or withdrew from active participation in follow-up research. Data available for intake and 18 months follow up.

Interventions
Intensive case management YP4 -Refers to young people and the four key aspects of the trial: purpose (employment), place (accommodation), personal support, and proof (research). YP4's joined up service delivery centred on intensive client-centred case management, involving direct provision of a range of services as well as the brokering of additional services, all through a single point of contact-the YP4 case manager. J group participants were eligible for joined up services for 18 months to 2.5 years. During this time, there was no time limit, no amount of service limit, and no cessation of eligibility because of success in reaching goals. Thus the intervention was not standardized in terms of duration and intensity. The defining feature was that J group participants remained eligible for joined-up services, and were entitled to re-engage with those services at any time during the service delivery phase of the trial. At the end of the service delivery phase of the trial, J group reverted to being eligible for standard services.

Interventions
Critical Time Intervention (9-month Case management) -While living in the transitional residence, all participants received basic discharge planning services and access to psychiatric treatment. After discharge, participants in both conditions received a range of "usual" community-based services depending on the individual's needs, preferences and living situation. These services usually included various types of case management and clinical treatment. 12 participants (8%) were assigned to mandatory outpatient treatment and/or assertive community treatment programs.
-In addition to the services noted above, participants randomly assigned to the experimental condition received nine months of CTI following discharge from the transitional residence. Post-discharge housing arrangements were typically coordinated by discharge planning staff located at the transitional residence. These arrangements ranged from community residences and other structured programs to supported apartments and independent housing, either alone or with family members. Neither CTI workers nor research staff were involved in determining the initial housing arrangement for individuals in either condition. Some individuals left the transitional residence "against medical advice" and returned to shelters or the streets but were nonetheless retained in the study.
-CTI is a nine-month case management intervention delivered in three phases, each of which lasts approximately three months (see Table 1). o Phase one--transition to the community--focuses on providing intensive support and assessing the resources that exist for the transition of care to community providers. Ideally, the CTI worker will have already begun to engage the client in a working relationship before he or she moves into the community. This is important because the worker will build on this relationship to effectively support the client following discharge from the institution. The CTI worker generally makes detailed arrangements in only the handful of areas seen as most critical for community survival of that individual. o Phase two-try out--is devoted to testing and adjusting the systems of support that were developed during phase one. By now, community providers will have assumed primary responsibility for delivering support and services, and the CTI worker can focus on assessing the degree to which this support system is functioning as planned. In this phase, the worker will intervene only when modification in the system is needed or when a crisis occurs. o Phase three-transfer of care--focuses on completing the transfer of responsibility to community resources that will provide long-term support. One way in which CTI differs from services typically available during transitional periods is that the transfer of care process is not abrupt; instead, it represents the culmination of work occurring over the full nine months.
-CTI was delivered by three workers trained by several of the model developers. Two were bachelors level employees of the NYS Office of Mental Health re-assigned to this project from their regular duties. The third worker, who also performed some supervisory activities, was a more experienced worker who had previously delivered CTI in an earlier trial. Weekly supervision was carried out by clinically trained staff experienced in the model.

Interventions
Case management and Section 8 program (CM+S8) Comprehensive case management or the traditional level of case management available in San Diego County. Comprehensive case management was provided by a mental health service under contract with the county and differed from the traditional condition in several respects. Comprehensive case managers had a smaller case loads, were constantly available, and had higher salaries. They took a formal team approach to working with clients, attempted to establish housing support groups for participants in housing, and tried to work with clients on finding employment. Section 8 is a federal program allowing certificate holders to pay a fixed 30% of their income for a private rental unit. Section 8 certificates do not require that individuals live in special lowincome housing, but encourages private housing in the community that meets their personal needs and the constraints of their income. Two requirements: housing must meet the quality standards of HUD (the US Department of Housing and Urban Development) and the rent for the unit must be equal or less than fair market rent for the area. Application process tailored to meet needs of mentally ill individuals. Single housing specialists, sensitive to the limitations imposed by severe mental illness, process applications. Structure rules (e.g. keeping appointments) are relaxed. Case managers worked closely with participants as they navigated the Section 8 application process, selected living arrangements, and moved into independent housing. A formal team approach to was taken working with clients, attempted to establish housing support groups for participants in housing, and tried to work with clients on finding employment.

Outcomes
Stably housed: The stable housing category included clients consistently living independently in apartments, and those who had consistent community housing but were not living independently. At least 80% of the days in one of the first three two-months intervals were spent in independent housing, and at least 80% of the days reported between month 7 and 24 were spent in independent housing or at least 90% of the days reported between the months 19 and 24 were spent in independent housing, and at least 80% of the days in each of the last three two-month intervals were spent in independent housing. Homeless: those neither stably, variably, nor institutionalized reporting data for 12 months or more.
Institutionalized: Hospital or skilled facility, jail/prison. Episodically institutionalized: spent at least 10% of four months intervals between month 7 and month 24 in an institution.
Consistently institutionalized: at least 90% of days between month 7 and 24 in an institutional setting.
Variably housed: spent time in some type of housing, and no more one two-month interval between month 7 and month 24 were more than 10% of time spent in no housing or at least 90% of days between month 7 and 24 were spent in some housing. Other: Alcohol use, Drug use Measurement: Housing status was assessed over a two-year period using monthly housing information provided by case managers. Sixty-day calendar self-report data in the interviews provided a supplement to case managers' reports. Criteria for each housing situation included that at least 80% of the days reported between months 7 and 24 were spent in a specific type of housing (e.g., independent housing) or that at least 90% of all reported days between months 19 and 24 were spent in a specific type of housing. Data available at intake and at 24 months follow up.

Interventions
Abstinent-contingent housing (ACH) with day treatment ACH groups were charged $161 per month to remain in program housing. Funds could be earned through work therapy but participants were not removed from housing if they failed or were unable to pay. In Phase I, participants received furnished, rent-free, abstinence-contingent housing (i.e., a furnished apartment with flatware) after two consecutive drug-free urine tests. This housing was a treatment intervention (maximum 6 months) and not a permanent housing program. Twiceweekly urine testing was required of all participants. For abstinence-contingent housing participants, a positive urine test caused immediate removal from housing and transportation to a shelter; with two consecutive clean urines, the subject could return to program housing. All participants were eligible to seek housing referrals from the host agency or any other agency in the city. The first 6 months of treatment included a combination of day treatment and paid work therapy developed over two previous trials funded by the National Institute on Drug Abuse, provided at BHC under direction of the investigators. This program was divided into phase I (day treatment, months 1-2), Phase II (work therapy and aftercare, months 3-6), and an additional 6 months of once-weekly aftercare group meetings and individual counseling, if desired. Phases I and II were designed to build a nondrug-use-based repertoire of activities, rewards, and sources of self-efficacy. Conditionality of tenancy: housing is contingent on sobriety, on leaving urine samples, and on no severe misbehaviour Housing provision: no information Segregation: no information Case management intensity: no information on whether services were organized in the form of case management. Non-abstinent-contingent housing (NACH) with day treatment NAHC participants received equivalent program as abstinence-contingent housing participants in a different neighborhood after offering two urine samples, regardless of results. Housing program was similar to abstinence-contingent housing, non-abstinence-contingent housing groups were charged $161 per month to remain in program housing. Funds could be earned through work therapy but participants were not removed from housing if they failed or were unable to pay. In Phase I, non-abstinence-contingent housing participants received furnished, rent-free, abstinence-contingent housing (i.e., a furnished apartment with flatware). Non-abstinencecontingent housing participants remained in housing as long as they provided two urines per week, regardless of result. This housing was a treatment intervention (maximum 6 months) and not a permanent housing program. The first 6 months of treatment included a combination of day treatment and paid work therapy developed over two previous trials funded by the National Institute on Drug Abuse, provided at BHC under direction of the investigators. This program was divided into phase I (day treatment, months 1-2), Phase II (work therapy and aftercare, months 3-6), and an additional 6 months of once-weekly aftercare group meetings and individual counseling, if desired. Phases I and II were designed to build a nondrug-use-based repertoire of activities, rewards, and sources of self-efficacy. Conditionality of tenancy: housing is contingent of leaving urine samples, and on no severe misbehaviour Housing provision: no information Segregation: no information Case management intensity: no information on whether services were organized in the form of case management. Day treatment (no housing) NH Participants were free to seek their own accommodations while receiving the same outpatient treatment program, and they typically stayed in residential recovery homes or shelters. Participants were eligible to seek housing referrals from the host agency or any other agency in the city. The first 6 months of treatment included a combination of outpatient treatment and paid work therapy developed over two previous trials funded by the National Institute on Drug Abuse, provided at BHC under direction of the investigators. This program was divided into phase I (day treatment, months 1-2), Phase II (work therapy and aftercare, months 3-6), and an additional 6 months of once-weekly aftercare group meetings and individual counseling, if desired. Phases I and II were designed to build a nondrug-use-based repertoire of activities, rewards, and sources of self-efficacy.

Conditionality of tenancy: not applicable
Housing provision: not applicable Segregation: not applicable Case management intensity: no information on whether services were organized in the form of case management.

Outcomes
Stably housed: days spent in the following settings: own apartment/house, parent/guardian's apartment/house, own single-resident occupancy (SRO), boarding house, or board and care facility, group home and long-term alcohol/drug free facility. Settings such as shelter, treatment, or recovery program (including those within shelters), corrections/halfway house, hospital, jail/prison, did not qualify.

Interventions
Assertive community treatment (ACT) and enhance housing opportunities The ACTteam: 12 full-time equivalent staff, including a program director with a masters' degree in social work, a full-time psychiatrist and medical director, 6 clinical case managers (social workers, psychiatric nurses, and rehabilitation counselors), 2 consumer advocates, a secretary receptionist, a part-time family outreach worker from the alliance for the Mentally Ill of metropolitan Baltimore, and a part-time nurse practitioner to treat chronic medical problems. Each patient was assigned to a "mini-team" consisting of a clinical case manager, an attending psychiatrist, and a consumer advocate. The entire ACT team, including the consumer advocates, worked together in decision making and each staff member was acknowledged about most of the patients. Team work was fostered through daily sign-out rounds and twice-weekly treatment planning meetings. Enhanced housing opportunities: 40 additional Urban Development Section 8 vouchers were allocated by the city wide mental health authority for the project and were available to the subjects on first-come first-served basis. Also, the grant expanded a transitional homeless shelter by 10 beds to provide more access to immediate temporary shelter for the subjects. This shelter program provided case management for the comparison clients. Hence, the experiment occurred in a somewhat enriched housing environment that which existed for other homeless persons in Baltimore. Conditionality of tenancy: possibly no conditionality for Section 8 vouchers Housing provision: possibly market provision for Section 8 vouchers Segregation: possibly non-segregation for Section 8 vouchers

Participants
Eligibility families with at least 1 custodial child living in the New York City family shelter system who were certified for Advantage subsidies and who had either (1) at least 2 prior stays in that system in the previous 5 years (episodic) or (2) at least 1 prior stay in that system in the previous 5 years that ended with the family moving into subsidized housing (recidivist). Sample Age (mean (SD)): Tx=33.5 (8.7), Control=33.9 (7.2) No other sample characteristics reported Location: NYC, USA

Interventions
Home to stay -Intensive case management -Designed to rapidly obtain and maintain housing for episodic and recidivist homeless families through intensive, temporary support services coupled with a time-limited housing subsidy.
-Partnership between a NYC charity, non profit service providers and NYC government.
-Services focused on 3 strategies: o Moving families out of shelter rapidly using a locally funded, temporary housing subsidy o Securing sufficient household income to enable families to pay market rent on expiration of the subsidy o Connecting families to community-based services that would help them to maintain housing stability after the termination of Home to stay services.
-Caseworkers met with client families at homeless shelters to encourage them to voluntarily enroll in Home to Stay services. Each enrolled family was assigned a single caseworker who followed them from shelter into permanent housing to ensure continuity services across that transitional period.
-Initial services focused on helping families to secure permanent housing and exit shelter as quickly as possible.
-Once client families were placed in housing, services focused on their obtaining a monthly household income equal to at least 200% of the family's rent obligation, obtaining a permanent housing subsidy, or both within 1 year of shelter exit.
-Because the availability of permanent subsidies was extremely limited, services primarily focused on maximizing income from public benefits for all eligible household members and obtaining or increasing employment income for all adult household members.
-Common elements of the case management model for all service teams included caseloads of 10 to 15 client families per worker, early and aggressive engagement to enroll clients while they were in shelter, flexible scheduling that accommodated clients' other time demands, individualized service plans informed by an assessment of clients' needs and strengths and were developed collaboratively with clients, financial literacy services integrated into case management, and frequent contact appropriate to clients' needs (beginning with at least 4 contacts per months, including at least 1 in situ face-to-face contact.
-Home to stay clients also remained on the caseloads of their standard services caseworkers and housing specialists.
-The program elements differentiating home to stay from standard services were more frequent client contact, smaller caseloads, flexibly scheduling, integrated financial literary services, and continuity of services across the transitional period from shelter into housing.

Interventions Case management
Case-managers chose how much time to offer each subject. As a minimum, each was offered an assessment of need from a case manager, a discussion of the findings of this assessment with the subject's carer, intervention from the case-manager to meet needs that were identified, monitoring of the subject's progress by the case-manager, and further assistance should needs arise. In addition, case-managers were free to choose how far they would personally assist the subject with transport, counselling, organisation of activity programs, assistance with completion of forms, crisis intervention, help with finding accommodation, assistance with benefits, finding work or places on training courses, and help with obtaining furnishings and domestic appliances.

Interventions
Parallel housing services with assertive community treatment (PHS+ACT) The program is close to the "supported housing model" and was implemented by several multidisciplinary teams, the services were implemented by mobile outreach teams from three mental health agencies that operated in distinct regions in DC, and the program more closely resembled a traditional supported housing approach. ACT is likely to use a shared-caseload approach. PHS and IHS provided similar case management services. PHS had consistently higher ratings than IHS on team approach, psychiatrist on staff, nurse on staff, and vocational specialist on staff. IHS had higher ratings than PHS on individualized substance abuse treatment and dual-disorder treatment groups. Conditionality of tenancy: continued tenancy is not contingent upon participation in clinical services and there is no live-in support staff Housing provision: the consumer selects the housing from "mainstream" options that are owned and managed by community landlords or housing agencies Segregation: housing is integrated within the community; that is, mental health consumers are not segregated in housing Case management intensity: high, case load 1:15, availability 24/7 (is indicated) Integrated housing services with intensive clinical case management (IHS+ICM) The program is close to the "continuum housing model" and was implemented by several multidisciplinary teams, the services were implemented by five teams within a single provider agency in DC, and the program included aspects of the traditional continuum model. Clinical case management is less likely to use a shared-caseload approach. PHS and IHS provided similar case management services. PHS had consistently higher ratings than IHS on team approach, psychiatrist on staff, nurse on staff, and vocational specialist on staff. IHS had higher ratings than PHS on individualized substance abuse treatment and dual-disorder treatment groups.

Interventions
Contingency management +: Participants were immediately provided with a furnished and rent free apartment which was contingent on continued sobriety during phase I (weeks 2-8).
Urine tests were carried out regularly and within six hours of a positive test participants were moved to shelter and could only return to their apartment after three consecutive negative urine tests. Participants began receiving vocational training immediately (four days a week for 3.5 hours per day). In Phase II (weeks 3-24) participants were required to pay a small amount of rent (not specified) from program provided stipends. Participants who maintained abstinence were moved to a transitional housing program funded by the national housing department (HUD). In Phase III continued tenancy in abstinence-contingent program housing was only available when space was available at a modest rent. Contingency management: Control group participants received the same abstinencecontingent housing, vocational training and work therapy as participants in the intervention group, but were not offered day treatment based on the community reinforcement approach. (1) Assertive community treatment. Two teams were established in Copenhagen, each with one senior psychiatrist, one psychologist, one or two nurses, one occupational therapist, one social worker and a vocational/educational guide (who served in both teams). The caseload did not exceed 10 patients per case manager. One primary person was responsible for maintaining contact, coordinating treatment and treatment adherence. The patients were also visited weekly when hospitalized. During admission, however, treatment responsibility was transferred to the hospital. These teams treated patients allocated to OPUS in the two-armed and three-armed randomization. The average number of patients in the teams was 60.
(3) Psycho-educational family treatment. As in hospital-based rehabilitation, but the multifamily groups continued for 1.5 years with approximately 40 sessions. The therapists were externally supervised.
(4) Social skills training was inspired by the model described by Liberman et al. (1986). Patients with impaired skills were offered training in groups with a maximum of six participants. There were two therapists, one of whom was a psychologist. The training consisted of modules: medication self-management; coping with symptoms; conversational skills ; problem solving; conflict management. Patients who did not need training received individual psycho-education from the primary staff member. Most patients were offered treatment at a community mental health centre after discharge. They were usually seen in the office, each patient being in contact with a physician, a community mental health nurse and a social worker. The caseload of the staff in the community mental health centres varied between 1:20 and 1: 30. Standard treatment consisted of the following elements: (1) Admission. Decisions on the need for hospitalization or out-patient treatment were made as usual. Patients in standard treatment and OPUS patients were admitted to the same psychiatric departments as patients not included in the trial. The patients in standard treatment did not receive the experimental interventions. Patients in standard treatment seldom met the therapists from the local community mental health centre before they were discharged to follow-up treatment at the centre.
(3) Psycho-educational family treatment. A minor proportion of the patients were offered supportive contacts with members of their families or educational groups for relatives.

Interventions Department of Housing and Urban Development (HUD) and US Department of Veterans Affairs (VA) Supported housing program (HUD-VASH)
Through an interagency agreement, HUD allocated funds for approximately 1000 housing vouchers for a program providing housing and case management assistance for literally homeless veterans with psychiatric or substance abuse problems or both. The essential feature of the program is that participants were offered priority access to Section 8 housing vouchers, authorize payment of a standardized local fair market rent which is less than 30 % of the individual beneficiary´s income. Case managers united veterans with the local housing voucher and helped them to; 1) locate an apartment, 2) negotiate the lease and 3) furnish and move into the apartment.
The majority of the case managers were social workers and nurses who encouraged counseling regarding substance abuse and employment. Conditionality of tenancy: each veteran had to agree to a treatment plan involving further participation in case management and other specified services if randomized either HUD-VASH or case management only Housing provision: Section 8 vouchers, housing not provided by care giver Segregation: no information, probably not segregated Case management intensity: unclear, CM-model modified from ACT-model, encourages weekly face-to-face contract, community-based service delivery and more intensive involvement in situations of crisis. No further details. Intensive Case management only (ICM) Case managers united veterans with the local housing voucher and helped them to; 1) locate an apartment, 2) negotiate the lease and 3) furnish and move into the apartment. The majority of the case managers were social workers and nurses who encouraged counseling regarding substance abuse and employment. Case managers were to provide the same intensity of services as in the HUD-VASH condition and were encouraged to use whatever housing resources they could obtain for the veterans.

Interventions
Family Critical time intervention -Community based care management in three phases of 3 months each (a) Transition to community; (b) Try-out; (c) Transfer to care -Designed to strengthen family members' long-term ties to the services they need, heal and strengthen maternal relationships with extended families and friends, and provide emotional and practical support during the critical time of transition from homelessness to stable housing in the community. FCTI focuses on the relationship between the case manager and mother that progresses through the 9 month period. -3 primary differences between FCTI and services as usual: (1)  Housing and homeless services as usual -All families entered the country homeless shelter system that provided for the placement of homeless families, singles, and childless couples in shelter facilities, transitional residences, and emergency housing. The system has been considered service-rich and well-coordinated; housing and homeless services represented one program in an array of socials services provided through the country to address the needs of low-income households, including employment services, child support services, family and children's services, medical/home care services, and temporary financial services. In 2004, housing and homeless services also began administering homelessness prevention programs, including a rental assistance program.
-Upon entry into the shelter system, families received a comprehensive assessment of needs over a 2 week period while staying in a 100 room former hotel. Parents and children were screened for problems in the areas of medical, mental health, substance abuse, and education. Clinical and nonclinical interviews explored families' pathways to homelessness, housing history, income and employment, education, and challenges faced by families. Each family received an independent living plan with treatment and service recommendations as deemed necessary by shelter staff. Typically, these plans included personal goal setting, communication, housekeeping and parenting skills, and referrals for any needed treatment. In addition, county social services staff and outside agency representatives provided full-time and part-time, onsite and offsite services to homeless households through contractual affiliations with and referrals to county nonprofit and private service providers.
-Families remained at the assessment center an average of 30 to 45 days while waiting for referral to their next placement in the shelter system. Referrals were made to 1 of 4 other shelters managed by nonprofit agencies. Sites varied in size (25-100 families) and living arrangements (converted hotel, new buildings with kitchen, apartment buildings). Sparsely furnished, relatively overcrowded and lacked privacy. Shelter sites typically provided basic onsite services that included, but were not limited to physical and mental health assessment and treatment; case management, substance abuse screening and rehabilitations; childcare, recreation and after school programs, parenting, adult education, life skills and job readiness programs; and home-finding program. Shelter personnel provided many of the onsite services.
-Stay durations ranged from a few months to more than 2 years. IF families were not able to move out with the use of personal resources, they stayed until they were evaluated by shelter staff as being housing ready (capable of finding and maintaining a permanent dwelling). Families then moved to transitional apartments designed as a step between living in a shelter and obtaining permanent housing. Transitional housing was provided with case management paid through a per diem rate that varied by provider contract and family size. To remain eligible for housing, families needed to work toward achieving housing readiness goals in specific areas, as designated in their independent living plans. Services provided often included counseling, treatment, services for specific health and mental health issues, and assistance with obtaining and maintaining permanent housing.
-Access to subsidized housing was difficult. (2) invitation to low-demand environment with resources (showers, food) 7am-7pm, structured group activities possible but not required, available assistance in obtaining health, mental health, dental, and social services and in developing and implementing individual rehabilitation plans, socializing opportunities; (3) respite housing in 10-bed shelters or rooms in blocks rented by program and overseen by staff; (4) in-community and on-site rehabilitation services to assist individuals in finding and maintaining community-based housing. Choices was staffed by 6 rehabilitation specialists (who received extensive training and ongoing supervision from Boston University) and respite staff (oversaw respite housing and operated the center weekends/holidays). Many respite staff were former homeless and in recovery from alcohol or substance abuse; a psychiatrist (weekly informal consultations), a public health nurse (8 hours per week) Conditionality of tenancy: low level of conditionality, emphasis on consumers choice, no further information Housing provision: partly care provided housing, 2700 units of specialty housing for persons with mental illness were developed through a joint city/state program, choices first developed relations with the supported apartment program and then initiated an own supported apartment program. Segregation: partly, housing varied from structured community residences to independent apartments Case management intensity: high, case load 1:13, no information on availability (probably 24/7). Usual care (UC) UC: structurally segmented and transitionally oriented, engagement with multiple programs and caregivers to negotiate a pathway out of homelessness. UC included a range of programs for homeless and specialty programs for homeless with mental illness, including outreach services, drop-in centers, case management programs, mental health and health services, soup kitchens, municipal and private shelters, and specialized municipal shelters for persons with psychiatric disabilities. Conditionality of tenancy: yes, a strong normative orientation in which set pathways in and out of services are prescribed and adherence to behavioral norms are mandated for successfully obtaining and maintaining housing (e.g., remaining sober as prerequisite for entry into a community reintegration program) Housing provision: partly care provided housing, 2700 units of specialty housing for persons with mental illness were developed through a joint city/state program. Segregation: partly, housing varied from structured community residences to independent apartments Case management intensity: no information

Interventions
Case management -Using a strengths-based case management (CM) model, case managers seek to link participants to resources within the community.
-The case manager reviews each of six general areas with the participant to gather a history and picture of the current situation: (1) housing needs; (2) health/mental health care, including alcohol/drug use intervention; (3) food; (4) legal issues, (5) employment and (6) education.
-Consistent with a strengths-based CM approach, the case manager takes responsibility for securing needed services for the youth and remains a support for the youth as he/she traverses the system of care.
-The strengths-based approach also includes the following features: 1) dual focus on client and environment, 2) use of paraprofessional personnel, 3) a focus on client strengths rather than deficits, 4) a high degree of responsibility given to the client in directing and influencing the intervention that he/she receives from the system and the outreach worker.
-Once this review is complete, an initial intervention plan is developed with specific goals and objectives.
-A manual and goal development sheets were developed by the first author. Service is not restricted to the office and includes transportation of clients to appointments, interviews, and related activities. Training included manual review, didactic training and extensive role play over a period of 2 days, as well as weekly supervision with audiotape review with the intervention supervisor throughout the study. Therapists included master's level counselors, marriage and family therapists or social workers. Case managers were bachelor's level social work students, and counseling was not provided. Conditionality: NA Housing provision: NO Segregation: NA Case management intensity: once per week, during the initial treatment phase, counseling sessions may be scheduled more frequently than once per week. The intervals between sessions can then be extended as the client's abstinence becomes more stable Motivational Enhancement therapy -Assumes that the responsibility and capability for change lie within the client, and need to be evoked (rather than created or instilled).
-Four principles guide the practice of MI: express accurate empathy, develop discrepancy, roll with resistance and support self-efficacy.
-An adaptation of MI that has been well-tested, both with adults and with adolescents, is motivational enhancement therapy (MET) which includes feedback.
-Although the frequency of MET sessions was lower than the other treatments, the duration of the treatment was matched with the other, longer treatments so that sessions were spaced over the course of the treatment period.
-Training included manual review, didactic training and extensive role play over a period of 2 days, as well as weekly supervision with audiotape review with the intervention supervisor throughout the study. Therapists included master's level counselors, marriage and family therapists or social workers. Case managers were bachelor's level social work students, and counseling was not provided. Conditionality: NA Housing provision: NO Segregation: NA Case management intensity: the frequency of MET sessions was lower than the other treatments, the duration of the treatment was matched with the other, longer treatments so that sessions were spaced over the course of the treatment period Community reinforcement approach CRA is an operant-based therapy with the goal to help individuals restructure their environment so that drug use or other maladaptive behaviors are no longer reinforced and other positive behaviors are reinforced.
-CRA treatment procedures are detailed in a book written by the developers (Meyers & Smith, 1995).
-Therapists follow a standard set of core procedures and a menu of optional treatment modules matched to clients' needs, including (1) a functional analysis of using behaviors, (2) refusal skills training, and (3) relapse prevention (4) job skills, (5) social skills training including communication and problem-solving skills, (6) social and recreational counseling, (7) anger management and affect regulation.
-Each area of focus is determined based upon the goals of counseling, and intervention components are repeated until the participant and therapist agree that the goal has been achieved.
-The intervention is tailored to the unique needs and environmental context of individual clients, so it is easily adapted to the multiple and various circumstances of those experiencing homelessness (e.g., limited recreational/social reinforcers).
-Training included manual review, didactic training and extensive role play over a period of 2 days, as well as weekly supervision with audiotape review with the intervention supervisor throughout the study. Therapists included master's level counselors, marriage and family therapists or social workers. Case managers were bachelor's level social work students, and counseling was not provided.

Participants
Eligibility: Homeless (chronic) and alcohol dependence Sample description: mean age 38, women 14%, most participants identified as white (64%). Details on mental illness, substance use, homeless status and criminal background were not reported Location: Albuquerque, New Mexico, USA

Interventions
Community Reinforcement Approach (CRA) Assumption: environmental contingencies play a powerful role in encouraging or discouraging drinking. CRA uses social, recreational, familial, and vocational reinforcers to assist clients in reducing their alcohol intake. CRA offers a multifaceted approach to alcohol treatment that addresses many of the needs of homeless individuals. CRA therapists: behaviorally oriented advanced clinically psychology graduate students trained in the CRA protocol. The CRA skills-training groups were offered on weekdays at the shelter, focused on problem solving, communication, drink refusal, independent living goal setting. A disulfiram compliance group was conducted daily for individuals who were taking disulfiram. The project nurse and the group members served as the monitor. Additionally a social club event was held weekly off-site in an effort to provide a reinforcing nondrinking recreational activity, a job club was run (e.g. for job seeking assistance), and couples therapy was offered to CRA group members with partners. CRA is not a CM intervention but a treatment model for homeless persons with alcohol dependence. Treatment length varied according to individual needs. In general CRA participants were expected to attend groups full time for a minimum of 3 weeks and to remain involved in the program while living in grant-supported housing. Hosunig is transitional: normal length of stay 3 months, individuals with secured job and saved agreed-upon amount of money could remain a 4th month. Apartments were shared by 2-4 participants. Conditionality of tenancy: abstinence was required when living together in grant-provided housing; Random Breathalyzer tests used at the apartments, offenders were suspended from housing for 1-2 weeks; individuals allowed to return once attended CRA groups sober daily during week of suspension Housing provision: grant-supported apartments. Segregation: no information Case management intensity: not applicable Usual care Day shelter's services, free meals, showers, clean cloths, telephones, and mail services. Additionally, a master's-level 12-step substance abuse counselor with 17 years of experience offered individual sessions, Alcoholics Anonymous (AA) meetings were held onsite, and job program arranged temporary employment. Finally, case managers were available for the dually diagnosed. Conditionality of tenancy: abstinence was required when living together in grant-provided housing; Random Breathalyzer tests used at the apartments, offenders were suspended from housing for 1-2 weeks; individuals allowed to return once attended CRA groups sober daily during week of suspension Housing provision: grant-supported apartments. Segregation: no information Case management intensity: case management only for dually diagnosed, no information on intensity

Outcomes
Stably housed: independent living, including paying for a more permanent dwelling, no further information Homeless: not stably housed (extrapolated) Measurement: no information, data available for intake and 12 months follow up.

Participants Eligibility
Diagnosis of a major mental illness; Significant treatment history, such as state hospitalization for a minimum of 60 days within the past 2 years; continuous attendance at a community mental health service for 3 or more years; five or more face-to-face contacts with a psychiatric emergency service within the past 2 years: Disability as indicated by a Global Assessment Scale (GAS) 27 score of 40 or below if the patient is over; age 35 and 60 or below if the patient is age 35 or younger. The nonconsumer team, part of a community mental health center, was supervised by a case manager supervisor who oversaw another team as well. In the second year of the project, the nonconsumer team added two part-time specialists who worked with the case managers. They performed such functions as helping in crisis situations, engaging in social activities with clients, and generally filling in when a case manager was on vacation. This arrangement was instituted when one of the case managers reduced her time. While there were changes in the composition of the two teams based on the desires of the supervising organizations, the integrity of the service conditions remained, as one team was composed of consumers and the other of the more customary nonconsumer case managers. The nonconsumer team, during the course of the 2year period, lost one case manager, and the consumer team lost three case managers. The nonconsumer team met biweekly and received individual supervision from the intensive case management supervisor/clinical director on a weekly basis. They also met with another team of intensive case managers on a monthly basis.

Interventions
Case management Site of service: community and hospital Team structure: individual case loads Hybrid between brokerage and full-service models and included elements of service brokerage (advocating for client entry to programs) and counselling (continuing contact with patients through a 1 year period). Case managers focused on linking patients with services that included medical care, psychiatric treatment, legal assistance, and social service entitlements such as low-income housing and supplemental security income (SSI). Case managers made appointments for evaluation and follow-up care and accompanied patients to these appointments. They educated patients about drugs, HIV, safe sex and helped them to obtain condoms and referred them to clean needle-exchange. Paraprofessionals, former consumers of HIV or substance abuse treatment services (abstinent for at least 2 years before starting work) and certified chemical dependency counsellors with successful work history in treatment programs with 1 week orientation to programs policies and procedures and supervision from licensed clinical social worker in the beginning of working.

Participants
Eligibility homeless or at risk, substance abuse (recruitment from detox treatment)

Sample description
The following is a description of the complete sample (all three trial arms): Approximately 78% of participants were available at the six month follow up, and 74% at the 12 month follow-up. The average age of the participants was 35 (data missing for two participants), approximately one quarter were female (25.5%) and 90% were African American. Participants had experienced almost 26 months of homelessness on average prior to the study (average of 18 of the previous 60 days homeless at baseline), and reported an average of approximately 18 days of alcohol/drug use in the 60 days prior to baseline. Location Chicago, Illinois, USA

Interventions
The progressive independence model case management Probably ordinary case management, but also provision of immediate tangible resourcestransportation tokens, food vouchers, medical care, and furniture and rent deposits (for those with long-term ability to support themselves) -while supporting further treatment for abuse and other relevant personal and situational problems. Provision is conditioned on attendance in outpatient and Alcoholics Anonymous meetings in the community and clients must remain abstinent from drugs and alcohol, and must sign a contract agreeing to cooperate with the (negotiated) treatment plan. Those who do not keep these agreements are first confronted with their behavior; if the problems continue, the clients are suspended, or askedto withdraw if the issues cannot be resolved. Individuals are required to progressively take responsibility for: obtaining employment, work training, or if neither is available, welfare benefits attending the project's group and individual counseling concerning intrapersonal, relationship, and permanent housing issues cooperating with a cognitive behavioral relapse prevention model that is utilized by case managers.

Conditionality of tenancy: not applicable
Housing provision: not applicable Segregation: not applicable Case management intensity: no information The progressive independence model case management and supported housing Same case management as above but also supported housing in one of three blocks of twenty apartments, found in recently renovated buildings serving those with low incomes. Those who suffered two relapses or repeatedly violated program rules could not remain in the housing. They could continue case management as long as they agreed to a new contract that would guard against further relapses. Conditionality of tenancy: abstinence, treatment compliance and program rules.

Interventions
Housing first with assertive community treatment (HF+ACT) HF provides permanent, independent housing without prerequisites for sobriety and treatment, and offers support services through consumer-driven ACT teams. HF promotes consumer choice, recovery, and community integration. Housing is separated from treatment. Addressing the consumer's needs first is the guiding principle for all subsequent services that are offered and is the foundation for building trusting and supportive clinical relationships. No indication of any deviation of ACT from original program. Conditionality of tenancy: HF programs offer immediate access to permanent independent housing, without requiring treatment compliance or abstinence from drugs or alcohol. Consumers can refuse formal clinical services, such as taking psychiatric medication, seeing a psychiatrist, or working with a substance use specialist, yet programs have requirements for a minimum of one visit per week by the team. As tenants, consumers remain housed as long as they meet the obligations of a standard lease. As in most supportive housing programs, consumers have an obligation to pay 30% of their income towards rent (typically, 30% of their Supplemental Security Income). The adverse consequences of relapse into substance abuse or a psychiatric crisis are mitigated because relapse is addressed by providing intensive treatment or facilitating admission to detox or hospital to address the clinical crisis -not by eviction because the consumer is using or experiencing psychotic symptoms. After completing treatment for their clinical conditions, consumers return to their apartments.
Housing provision: Apartments are rented from private landlords by the program, consumers have their own lease or sublease and have the same rights of tenancy as other residents in their buildings. HF offer housing in the form of scatter-site independent apartments in buildings rented from private landlords. Segregation: Housing is integrated. To maintain integration, the program does not lease more than 15% of the units in any one building.
Case management intensity: no information on case load (probably<1:15), availability 24/7. Usual care (UC) The county's usual array of services that included shelter-based programs and transitional housing.

Conditionality of tenancy: no information
Housing provision: no information Segregation: no information Case management intensity: no information

Outcomes
Stably housed: No definition, "permanent housing", "scattered-site housing" Homeless: no definition: shelter use, but not "permanent housing", not "scattered-site housing" Measurement: data were collected from administrative records as well as the respective Housing First agencies. Each month, the two Housing First agencies submitted reports to the Department of Social Services indicating the number of consumers whom they had outreached/engaged, the number of consumers currently remaining in housing, and the number of consumers no longer housed. Residential data for Housing First consumers were available continuously for just under four years (47 months). Residential data for control participants were obtained through the county's computerized shelter tracking system, but were only available at the 20-month time-point. Because data were not available for all three groups throughout the study follow-up period, two types of housing outcomes are presented. Housing status, was a single point-in-time count of the number of persons housed within the two Housing First groups and the control group at 20 months.

Interventions
Critical time intervention (CTl) A strategy to prevent homelessness by enhancing the continuity of care for individuals being discharged from institutional to community living. CTl creates a bridge between institutional and community care at a critical time in the deinstitutionalization process. CTI is intended for use by a broad range of institutions, including shelters, hospitals, and jails, and for prevention of first episodes of homelessness as well as recurrent homelessness. CTI is based on intensive case management (ICM). There are three phases preparing for the fourth phase when usual care begins: (1) Accommodation (1-3 months): CTI workers make home visits, accompany patients to appointments, meet with care givers, substitute care givers when necessary, give support and advice to patient and caregiver, mediate conflicts between patient and caregiver, help negotiate ground rules for relationships.
Housing provision: No specific information, a variety of usual services and housing in NYC. Segregation: No specific information, a variety of usual services and housing in NYC. Case management intensity: probably high intensity, CTI is a short and time limited form of intensive case management. No further information. Usual care (UC) Two phases Transition of services (1-3 months): shelter staff assist patients and caregivers upon request, and substitute for caregivers when necessary Usual services (4-7 months): services provided by community formal and informal supports, and patients and caregivers can phone for advice Conditionality of tenancy: no information Housing provision: no specific information, a variety of usual services and housing in NYC. Segregation: no specific information, a variety of usual services and housing in NYC. Case management intensity: no specific information.

Outcomes
Stably housed: extrapolated (not homeless) Homeless: night spent in a shelter or public space. Other: Psychiatric symptom severity (Positive and Negative Syndrome Scale Measurement: After randomization, face-to-face assessments were conducted every 30 days for 18 months. Trained interviewer blind to the client's group status, who documented where the client had spent each night. In cases in which a man had missed an assessment, the interviewer always documented the housing experience of each night since the last completed assessment. The man's residential experience was continuously traced for each night over the 18-month follow-up period. Occasionally, when a man could not be directly interviewed, the assessment was conducted with a key informant such as a close relative or a caseworker. Binary outcomes extrapolated from continuous outcomes. Data available at intake, 6, 12 and 18 months follow up.

Interventions
Demonstration Employment Project -Training and Housing (DEPTH/ICM) A holistic approach combining services concerned with job training/placement, locating permanent housing and support services, all targeted to the individual's specific needs and oriented toward the long-term goal of helping the person to escape homelessness. DEPTH addressed the clients' immediate tangible needs. For example funds were sometimes loaned to cover the security deposit for a new apartment and program staff helped clients obtain donated furniture and appliances and find quality day care for their children. Central to DEPTH's services was intensive case management, offering access and linkage to services (e.g. financial aid, housing support, counseling for drug and alcohol problems, mental health assessment and treatment, and job training). If appropriate services could be identified in the community, DEPTH staff would provide it. DEPTH adapted its model of intensive case management from a variety of sources, including ones from the mental health field.

Conditionality of tenancy: no information
Housing provision: no detailed information, a possible mix is indicated. Segregation: no detailed information, a possible mix is indicated. Case management intensity: DEPTH clients had a median of 41 staff contacts (averaging about 45 min) over a 4-to 8-month active intervention period. No information on case load or availability.
No-treatment control group (NT/UC) Those in no-intervention control group received none of the DEPTH's services, but were free to seek whatever other services were available to them in the community. Compensation for the lack of referral to DEPTH by seeking additional services in the community: research participants at each follow-up interview reported on services received in seven categories (i.e. impatient mental health or substance abuse care, outpatient mental health or substance abuse counseling, child or family counseling, financial counseling, vocational counseling, crisis services, and self-help groups). No significant group differences (p>.10) were found on any of these services and, overall, 59% of DEPTH clients received one or more of these services during the follow-up period, compared with 51% of the controls.

Interventions
Housing first with modified assertive community treatment (HF+ACT) A consumer's choice program: psychiatric rehabilitation for chronically homeless persons. Needs are addressed from the consumer's perspective, and are encouraged to define their own needs and goals and. Housing, a basic right. An apartment is immediately provided without prerequisites for psychiatric treatment or sobriety. Housing and treatment are separate domains. Consumers may accept housing and refuse clinical services without housing status consequences. A harm-reduction approach in clinical services regarding alcohol/drug abuse, psychiatric symptoms or crises. Consideration of consumers different stages of recovery, interventions are individually tailored to each consumer's stage. An Assertive Community Treatment (ACT) team, a community based inter-disciplinary team including social workers, nurses, psychiatrists, and vocational, substance abuse counselors and two additional team-workers: a nurse addressing health problems, and a housing specialist coordinating housing services (modifications of the standard ACT-model).
Conditionality of tenancy: no requirements regarding treatment compliance or sobriety. Tenants must pay 30% of their income toward the rent by participating in a money management program, tenants must meet with a staff member a minimum of twice a month, and follow standards rules for ordinary tenants. Requirements are applied flexibly to suit consumers' needs.
Housing provision: Housing is provided by the market, acquisition comes from landlord and brokers, but identification and negotiation is done by staff members of Pathways to Housing and temporary solutions are provided by the agency. Segregation: Housing is not segregated. Case management intensity: high, case load (no information), availability 24/7. Continuum of care, usual care (CoC/UC): Information is poor. The continuum of care model begins with outreach, includes treatment and transitional housing, and ends with permanent supportive housing. The purpose of outreach and transitional residential programs is to enhance clients' "housing readiness" by encouraging the sobriety and compliance with psychiatric treatment considered essential for successful transition to permanent housing. It is assumed that individuals with severe psychiatric disabilities cannot maintain independent housing before their clinical status is stabilized and that the skills a client needs for independent living can be learned in transitional congregate living. A typical program would be exemplified by a group home or a single-room occupancy residence in which clients are expected to attend day treatment, 12-step, and other therapeutic groups and follow medication regimens enforced by on-site staff. Sleeping, cooking, and bathing facilities are shared Conditionality of tenancy: Information is poor. Most programs have rules that restrict clients' choices and that when violated are used as grounds for discharging the consumer from the program. For example, despite having attained permanent housing, clients who relapse and begin to drink mild or moderate amounts of alcohol, may be evicted if the program has strict rules about sobriety maintenance. Continuum of Care supportive housing programs subscribe to the abstinence-sobriety model based on the belief that without strict adherence to treatment and sobriety, housing stability is not possible. The usual care programs offer abstinent contingent housing and services based on a treatment first model. House rules strictly prohibit consumption of any substances and overnight guests.
Housing provision: no information. Segregation: no information. Case management intensity: Information is poor, probably a variety.

Outcomes
Stably housed: residing in one's own apartment; or having a room or studio apartment in a supportive housing program, a group home, a boarding home, or a long-term transitional housing program; or living long-term with parents, friends, or other family members. Homeless: living on the streets, in public places, or in shelter-type accommodations. Measurement: number of days spent in any of the locations categorized as "homeless" was summed and divided by the total number of days of residency reported at the interview. Period was past 6 months. The mean percentage have here been multiplied with the number of persons in each group, and in this way the number of homeless persons have been estimated. Other: Substance use, psychiatric symptoms Measurement: number of days spent in any of the locations categorized as "stably housed" was summed and divided by the total number of days of residency reported at the interview. Period was past 6 months. The mean percentage have here been multiplied with the number of persons in each group, and in this way the number of housed persons have been estimated. Binary outcomes were extrapolated from continuous outcomes (graphically estimated). Data available at intake, 6, 12, 18, and 24 months follow up.