What is the existing evidence base for adult medical Same Day Emergency Care in UK NHS hospitals? A scoping review

Introduction This scoping review focuses on acute medical Same Day Emergency Care (SDEC), as medical patients represent a significant proportion of emergency admissions in the NHS. Methods This scoping review has been conducted in accordance with the JBI methodology and as detailed in the published scoping review protocol. Results Identified papers included two observational cohort studies, four audits, four review articles, two opinion pieces, a paper on potential future developments, three policy documents, one strategy paper and a position statement. Key themes were extrapolated and discussed in a narrative. Conclusions The scarcity of literature in relation to the quality, safety, and effectiveness of SDEC highlights the need for further study. Therefore, there is a pressing need for SDEC specific research within the UK.


Introduction
Building on previous work undertaken within ambulatory emergency care (AEC), to support non-admitted emergency care pathways, Same Day Emergency Care (SDEC) is a new model of care that has been developed within the NHS, 1 as mandated in 2019 by the NHS Long Term Plan; 2 the Same Day Strategy for SDEC was subsequently released in 2021. 3he model suggests that SDEC can meet local health needs by providing an alternative to emergency department (ED) attendance or hospital admission.SDEC services are considered essential to the future provision of acute care, in an aging society with limited health care resources. 3owever, as with AEC, considerable service variation exists within the SDEC model.Some organisations offer a broad range of specialties within their SDEC services: paediatric, frailty, gynaecology, surgery, oncology, in addition to acute medicine, whereas other organisations focus their SDEC model predominantly on acute medicine.Further, within Table 1 Search strategy.
Keywords: Same AND Day AND Emergency AND Care OR SDEC OR Ambulatory AND Emergency AND Care OR AEC, using Boolean operators Eligibility Criteria: Participants Adults (over 18) Concept Same Day Emergency Care model of care delivery and acute medicine specialty, excluded condition specific papers and papers relating to other specialties Context NHS hospitals in the UK admitted.Some services are developing this observational further, using Virtual Wards and Hospital at Home, 4 , 13 but these services are beyond the scope of this review, being beyond the immediacy of same day care.
An emerging evidence base suggests that ambulatory services in the UK may improve patient experience, reduce hospital admissions, infection risk and deconditioning and offer cost savings. 14However, ambulatory care provision has been heterogeneous, whereas SDEC now has a national strategy, with core requirements, 3 although local variations remain significant, in terms of speciality coverage; and some AEC services have simply been rebranded as SDEC.Embedding the SDEC national strategy should guide future service development in a more cohesive manner, leading to a more homogenous service across NHS regions.This in turn will support future research, as comparisons between services will be less varied.
Given that the SDEC model has been operational for a relatively short period of time, a review of the evidence base is indicated to establish what research supports the model.6][17] It remains to be seen whether medium-and long-term costs savings are produced by SDEC services, given the requirement for additional pathways, estate, and staffing, or whether this approach simply delays admission and/or increases severity of illness at presentation, particularly in the older, frail population.
Establishing existing evidence underpinning the SDEC model will identify gaps that require investigation through further research.9][20][21] The Joanna Briggs Institute (JBI) methodology for scoping reviews 22 was chosen to provide structure, and to support the development of a comprehensive overview of available evidence in relation to adult medical SDEC.
A preliminary search of MEDLINE, the Cochrane Database of Systematic Reviews, JBI Evidence Synthesis, and PROSPERO was undertaken to ascertain if this topic had been investigated previously, and no current, or in progress, systematic reviews or scoping reviews on the topic were identified.

Review question
What is the existing evidence base for adult medical Same Day Emergency Care in UK hospitals?

Objective
To determine the existing evidence base in relation to UK-based medical SDEC.

Types of sources
This scoping review considers all study designs, texts, and opinion papers for inclusion. 22

Methods
The methods follow the JBI recommended structure of: Search strategy; Study/Source of Evidence selection; Data Extraction; Data Analysis and Presentation, 22 followed by a narrative summary using a thematic approach.
A variety of evidence synthesis methodologies are available, including a range of different types of review, including systematic reviews, mixed methods reviews, realist syntheses, all aiming to inform policy, practice and/or further research, through rigorous, explicit, and systematised methods. 23If answers to clinically meaningful questions or to produce practice guidance are required a systematic review is likely to be the preferred review option, whereas to identify the types of evidence available in a particular area, to identify key characteristics or factors, and to identify and analyse knowledge gaps, a scoping review is likely to be more suitable. 20A scoping review offers an initial evaluation of the possible volume and range of existing literature; its primary goal is to recognise the nature and breadth of evidence for policy or practice, in contrast to systematic reviews. 21onsidering the objectives of this review, a scoping review was selected as the appropriate methodological approach to systematically identify and map the evidence, across a wide range of sources, relating to SDEC.This assists in clarifying the evidence base and identifies key characteristics and/or factors relating to SDEC, as well as noting and analysing gaps in knowledge to develop future research.Critical appraisal of individual sources of evidence is not normally required for scoping reviews, hence no subsequent critique is offered. 22he guidance provided by the JBI Manual for Evidence Synthesis, Chapter 11: Scoping Reviews 22 offers a robust, structured framework, that builds on and refines previous iterations of scoping review frameworks. 21This guidance recommends that an a priori protocol is required to support a systematic scoping review, accordingly a protocol was developed, registered, 24 and published. 25In further alignment with the JBI guidance the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for scoping review (PRISMA-ScR) guideline has been utilised for this review. 21 , 23 , 26

Search strategy
The search aimed to locate both published and unpublished studies.An initial limited search of MEDLINE and CINAHL, via EBSCOhost, was undertaken to identify articles on the topic.The words contained in titles and abstracts of relevant articles were used to develop a full search strategy ( Table 1 ), adapted for each database and/or information source, including all keywords.The reference lists of all included sources of evidence were screened for additional studies. 22tudies published in English were included, as this review focuses on UK-based SDEC services.Studies published in the past five years were included, due to the recent initiation of the SDEC model, the specific focus on SDEC, the general timeline for operation of SDEC, and the wideranging differences between the former heterogenous AEC services.Papers were only included where full text versions were immediately available.( Table 2 : Inclusion and Exclusion Criteria).

Table 2
Inclusion and exclusion criteria.

Inclusion criteria:
English language, within the last 5 years, full text available, UK only, Adults (over 18), acute medicine specialty.Exclusion criteria : Foreign language, older than 5 years, no full text available, non-UK papers, paediatrics (under 18), specialties other than acute medicine.

Fig. 1. Flow diagram of search.
The databases searched include EMBASE, MEDLINE and CINAHL, via EBSCOhost, during August 2023.Sources of unpublished studies, policies and grey literature searched comprised Google Scholar, the Cochrane Library, TRIP database, ProQuest Dissertations and Theses Open, and the Health Management Information Consortium.

Study/source of evidence selection
Following the search, all identified citations were collated and uploaded into EndNote Web 27 and duplicates removed.Titles and abstracts were screened by one reviewer against the inclusion criteria.Potentially relevant papers were retrieved in full.The full text of selected papers was assessed, against the inclusion criteria, by two reviewers.Reasons for exclusion of papers, at the full text stage, that did not meet the inclusion criteria were recorded and are reported. 22The results of the search and the study inclusion process are reported and presented in a PRISMA flow diagram ( Fig. 1 ).

Data extraction
Data was extracted from included papers by two reviewers, using a data extraction tool based on the JBI data tool; differences of opinion were discussed until consensus was reached. 22Extracted data includes specific details about the participants, concept, context, study methods, and key findings relevant to the review question.

Data analysis and presentation
Data from the extraction tools was summarised and is presented in tabular form in Table 3 .Types of papers and key concepts were identified and are presented in Table 4 .A word cloud was generated via a weighted list of key theme frequencies to illustrate key concepts ( Fig. 2 ). 28Discussion NHS England and NHS Improvement 2 mandated the implementation of SDEC in every hospital with an ED during 2019/2020 and is endorsed by The Royal College of Emergency Medicine (RCEM) and the Society for Acute Medicine, 29 this position statement espouses the benefits of SDEC as reducing unwarranted variation in care pathways, streamlining the patient journey, improved patient, and staff satisfaction, reducing admissions, and improving flow.However, as indicated in the papers identified ( Table 4 ), there is limited research relating to SDEC as a model of care, but several themes became apparent during analysis.

Factors required for success
Identifying factors required for success in operating SDEC is considered by several review articles and policies.

Patient selection -pathways vs process driven
Selecting the right patients for SDEC is key with 30% of patients presenting with an acute medical issue being suitable for management on SDEC. 30The need for clear pathways and processes for ensuring that the right patients are referred to SDEC is evident. 1 , 30 , 31 Cottrell et al. 11 recommend a process driven, ambulatory by default mind set, rather than condition specific pathways, a view supported by RCEM. 32The variation in SDEC service design and patient selection methods is highlighted by Atkin et al. 33 and Dean et al. 4 ; although the Same Day Strategy 3 should lead towards standardisation of services in the future.Indeed, this strat-egy promotes widening access, stating that SDEC should be available to all stakeholders, including primary care, ambulance services, out-ofhours services, and not just be considered for reassigning ED patients.

Early senior decision making and collaborative working
Having a senior decision maker in SDEC facilitates prompt review and allows early management and discharge decisions to be made. 11 , 30 , 31Although Cottrell et al. 11 go further and acknowledge that acute generalists, including advanced practitioners, acute medicine and ED doctors or GPs can offer expanded options for staffing SDEC with senior clinicians.This is notably the only mention evident of the contribution of advanced practitioners within SDEC in the literature.This is surprising, given workforce challenges and that the need for, and value of, advanced practitioners has been recognised for some years, 34 whilst the need for safe and sustainable staffing, 3 and collaborative working across specialties and traditional boundaries is recognised by some. 31 , 32

Rapid access to diagnostics
To facilitate assessment of patients within SDEC, access to rapid diagnostics, in the same timeframe as the ED, is required, this is a key factor for success, as without diagnostics decision-making for safe discharge is problematic. 11 , 31 , 32Achieving rapid access to diagnostics requires negotiation and potentially investment in diagnostic services to increase capacity.However, the growing ability of clinicians to undertake diagnostic medical ultrasound 35 will relieve some of the pressure on the diagnostic team if equipment is available on SDEC.Such point of care testing in SDEC also offers opportunities for rapid results on other investigations such as troponin and D-dimer, 33 but again requires investment.

Measures of success
There is a lack of clarity as to what metrics should be collected on SDEC to determine what success looks like.NHS Improvement and the Ambulatory Emergency Care Network 1 proposed metrics but these have not been widely adopted.RCEM 32 highlighted the importance of developing performance measures to assess impact, quality, and efficiency.The Same Day Strategy 3 commits to standardisation of monitoring and evaluation of process activity.NHS England 36 are committed to rolling out the 'ECDS' (Emergency Care Data Set) to record SDEC activity, separately from admitted patient care data, but contracting issues are posing a barrier and no implementation date has been set.Data is being collected on SDEC, but these are process data rather than clinical outcome data, for example: number of attendances, time spent on SDEC, admission and discharge within six hours, percentage of virtual consultations, and average weekly opening hours. 37n a single centre retrospective study, 10 hospital data on 16,497 patients was analysed for an adult medical SDEC service, seeking to establish activity and outcomes.In the last calendar year studied, the conversion rate from SDEC to inpatient admission was 12%, the 30-day readmission rate was 6.9% (18% for the admitted pathway).Across the 3-year period, 30-day mortality was 1.6%.There was a reduction in inpatient bed requirements.The conclusion drawn was that the SDEC approach is safe and effective, and within the limitations of a single-centre study, thus supports SDEC services.Using conversion to inpatient admission, 30-day readmission and 30-day mortality seem reasonable safety metrics, and the latter two permit comparison with inpatient admission data.
A comparative single centre study of an SDEC service within an acute admissions unit evaluated the period before and after the SDEC service opened to identify its impact. 38Reducing pressure on the ED and medical take, reducing time to clinical review and discharge were found to be benefits of improving the patient pathway, which are reasonable metrics on effectiveness.Reducing ED pressure was also a benefit highlighted 39 in a 4-day study looking at 33 patients taken directly from ED, after initial assessment, with two admissions resulting.
Baker 40 considered discharge and admission avoidance, and demonstrated improved admission avoidance, more targeted use of diagnostics and improved efficiency in a service review pre and post SDEC implementation.A short audit on direct streaming from ED to SDEC, demonstrated shorter length of stay and a high discharge rate for those seen within SDEC, it was identified that the traditional referral process between ED and acute medicine led to unnecessary admissions and delays in the patient journey, that can be ameliorated by rapid streaming to SDEC. 39t seems that clinically relevant outcomes are largely unknown when SDEC services are considered.As discussed by Atkin et al., 3 evidence of safety and positive impact on patient care is limited.Their literature review found some evidence, but this was generally confined to a few specific conditions, such as pulmonary embolus and low risk community acquired pneumonia.They conclude that no robust studies exist to demonstrate benefit for most conditions, and no studies of cost effectiveness have been undertaken in relation to SDEC.This view is shared by Cottrell et al. 11 who advise that outcome and experience metrics are needed.
Thompson and Connolly 30 discuss how patient experience is improved by managing care on SDEC, rather than through inpatient admission.But notably there are no published studies on the patient experience of SDEC.Patient satisfaction is a key measure of quality, the NHS England Experience of Care Group has recently undertaken a coproduction project to develop Quality Markers and Metrics for SDEC, 41 a project that the first author of this review was involved with; this collaborative project should lead to benchmarking across SDEC services and generate service improvement initiatives.

Barriers to success
Elias et al. 42 undertook a single centre prospective observational cohort study, in a multidisciplinary SDEC, with 533 older frail patients, aiming to understand factors associated with admission to bed-based care, concluding that conversion to admission is high in this cohort; this suggests that SDEC may not be effective in this population and illustrates the importance of selecting the correct cohort of patients for SDEC.
An audit of referrals pre and post the implementation of an SDEC, within an acute medical unit, demonstrated many inappropriate referrals, some requiring an alternate specialty review other than acute medicine, an expectation that SDEC would follow up inpatient tests post-discharge and a lack of medical 'hot clinics' i.e. capacity to see discharged patients within a few days. 43Standardisation and education on the purpose of SDEC will ameliorate lack of understanding amongst professionals, and robust standard operating procedures will support clinicians in declining inappropriate referrals.Organisations should consider whether acute medicine hot clinics should be implemented to follow up post-discharge patients, or whether these patients should be seen in SDEC, given that the hospital contract requires trusts to review these patients rather than discharge them for general practice review within days.
The risk of SDEC services being derailed by trusts repurposing these areas as inpatient areas during times of high demand remains a threat to SDEC provision. 44This concern is supported by Mahase, 45 citing data from the national Society of Acute Medicine Baseline Audit that only 22% of patients received their medical assessment and treatment in an SDEC setting.The underlying reasons were lack of investment in SDEC services and inappropriate use of SDEC, including using the area for escalation and converting it to a bedded area for inpatients in times of high demand.
The Same Day Strategy 3 requires suitable estate to facilitate the implementation of SDEC services within trusts.However, the availability of space within existing estate for the development of SDEC may be a barrier, along with the requirement for investment, as there are competing pressures on resources, and capital investment can be difficult to secure.

Areas where no papers were identified
There were no studies exploring patient experience of SDEC, nor of the workforce supporting SDEC services, such as the use of advanced practitioners in addition to, or instead of, medical staff.

Limitations
Scoping reviews present and summarise the papers identified; critical appraisal and risk of bias assessments are not required in scoping reviews; some methodologists suggest that this is a limitation, as they cannot be used as evidence to guide practice but are instead designed to identify gaps in the literature.In hindsight, limiting the search to the previous five years may have been too short, and resulted in valuable learning from the former iteration of SDEC -AEC, being excluded, but earlier papers have been used in this paper's narrative for contextualisation.

Recommendations and conclusions
Based on the features of SDEC services emerging from this review, it is recommended future SDEC research could usefully consider: • Clinical outcomes of medical patients attending SDEC, compared to those admitted to hospital for a short stay.Specific measures could include conversion to admission rate, readmission within 30-days, 30-day mortality.• Patient experiences of SDEC.
• Workforce studies -is there a variance in clinical outcomes or patient experience in services led by advanced clinical practitioners vs. senior medical staff, and associated cost-effectiveness of different staffing models.
SDEC is now a mandated requirement within the NHS in the UK and requires an underpinning evidence-base.The scarcity of literature in relation to the quality, safety, and effectiveness of SDEC highlights the need for further study.Whilst different organisations operate SDEC in variable ways, as to be expected in the complex systems within the NHS, more standardisation and reduction in variation will increase the ability to evaluate specific SDEC services and make comparisons between SDEC services.Therefore, there is a pressing need for SDEC specific research within the UK, such as this scoping review has noted.

Contributions
SD proposed the initial idea for reviewing the topic of SDEC.JB proposed the idea for utilising a scoping review approach.SD wrote the initial drafts of the paper and undertook the initial preliminary review of the literature for this paper.JB commented on and revised drafts of this paper and formatted the pre-submission draft.

Declaration of competing interest
There are no conflicts of interest in this project.

Table 3
Table of papers.