A Digital Peer Support Platform to Translate Online Peer Support for Emerging Adult Mental Well-being: Randomized Controlled Trial

Background Emerging adulthood (ages 19 to 25 years) is a developmental phase that is marked by increased mental health conditions, especially depression and anxiety. A growing body of work indicates that digital peer emotional support has positive implications for the psychological functioning of emerging adults. There is burgeoning interest among health care professionals, educational stakeholders, and policy makers in understanding the implementation and clinical effectiveness, as well as the associated mechanism of change, of digital peer support as an intervention. Objective This randomized controlled trial (RCT) examined the effectiveness of a digital peer support intervention over a digital platform—Acceset—for emerging adult psychological well-being with 3 primary aims. First, we evaluated the implementation effectiveness of digital peer support training for individuals providing support (befrienders) and of the digital platform for peer support. Second, we assessed the clinical outcomes of digital peer support in terms of the intervening effect on emerging adult psychological well-being. Third, we investigated the mechanism of change linking the digital peer support intervention to emerging adult psychological well-being. Methods This RCT involving 100 emerging adults from the National University of Singapore follows the published protocol for this trial. Results This RCT found effectiveness in digital peer support training—specifically, befrienders’ peer support responses demonstrating significantly higher post- than pretraining scores in selfhood (posttraining score: mean 62.83, SD 10.18, and SE 1.72; pretraining score: mean 54.86, SD 7.32, and SE 1.24; t34=3.88; P<.001). The digital peer support intervention demonstrated clinical effectiveness in enhancing selfhood, compassion, and mindfulness and lowering depressive and anxiety symptoms among seekers in the intervention group after the intervention (mean 7.15, SD 5.14; SE 0.88) than among seekers in the waitlist control group before the intervention (mean 11.75, SD 6.72; SE 0.89; t89=3.44; P<.001). The effect of the intervention on seekers’ psychological well-being was sustained beyond the period of the intervention. The mechanism of change revealed that seekers’ engagement with the intervention had both immediate and prospective implications for their psychological well-being. Conclusions This RCT of a digital peer support intervention for emerging adult psychological well-being harnesses the interventional potential of 4 components of psychological well-being and elucidated a mechanism of change. By incorporating and validating the digital features and process of a peer support platform, our RCT provides the parameters and conditions for deploying an effective and novel digital peer support intervention for emerging adult psychological well-being in real-world settings. Trial Registration ClinicalTrials.gov NCT05083676; https://clinicaltrials.gov/ct2/show/NCT05083676

CONSORT-EHEALTH (V 1.6.1) -Submission/Publication Form The CONSORT-EHEALTH checklist is intended for authors of randomized trials evaluating web-based and Internet-based applications/interventions, including mobile interventions, electronic games (incl multiplayer games), social media, certain telehealth applications, and other interactive and/or networked electronic applications. Some of the items (e.g. all subitems under item 5 -description of the intervention) may also be applicable for other study designs.
The goal of the CONSORT EHEALTH checklist and guideline is to be a) a guide for reporting for authors of RCTs, b) to form a basis for appraisal of an ehealth trial (in terms of validity) CONSORT-EHEALTH items/subitems are MANDATORY reporting items for studies published in the Journal of Medical Internet Research and other journals / scienti c societies endorsing the checklist.
As the CONSORT-EHEALTH checklist is still considered in a formative stage, we would ask that you also RATE ON A SCALE OF 1-5 how important/useful you feel each item is FOR THE PURPOSE OF THE CHECKLIST and reporting guideline (optional).
Mandatory reporting items are marked with a red *. In the textboxes, either copy & paste the relevant sections from your manuscript into this form -please include any quotes from your manuscript in QUOTATION MARKS, or answer directly by providing additional information not in the manuscript, or elaborating on why the item was not relevant for this study. Identify the mode of delivery. Preferably use "web-based" and/or "mobile" and/or "electronic game" in the title. Avoid ambiguous terms like "online", "virtual", "interactive". Use "Internet-based" only if Intervention includes non-web-based Internet components (e.g. email), use "computer-based" or "electronic" only if o ine products are used. Use "virtual" only in the context of "virtual reality" (3-D worlds). Use "online" only in the context of "online support groups". Complement or substitute product names with broader terms for the class of products (such as "mobile" or "smart phone" instead of "iphone"), especially if the application runs on different platforms.
C l e a r s e l e c t i o n Does your paper address subitem 1a-i? * Copy and paste relevant sections from manuscript title (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study subitem not at all important 1 2 3 4 5 essential 1a-ii) Non-web-based components or important co-interventions in title Mention non-web-based components or important co-interventions in title, if any (e.g., "with telephone support").
C l e a r s e l e c t i o n Does your paper address subitem 1a-ii?
Copy and paste relevant sections from manuscript title (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study Not applicable. No non-web-based components Your response is too large. Try shortening some answers. Does your paper address subitem 1a-iii? * Copy and paste relevant sections from manuscript title (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "for Emerging Adult Mental Well-being" Your response is too large. Try shortening some answers. Does your paper address subitem 1b-i? * Copy and paste relevant sections from the manuscript abstract (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study Information about key features/functionalities/components of the intervention and comparator are in the published protocol ( subitem not at all important 1 2 3 4 5 essential 1b-ii) Level of human involvement in the METHODS section of the ABSTRACT Clarify the level of human involvement in the abstract, e.g., use phrases like "fully automated" vs. "therapist/nurse/care provider/physician-assisted" (mention number and expertise of providers involved, if any). (Note: Only report in the abstract what the main paper is reporting. If this information is missing from the main body of text, consider adding it) C l e a r s e l e c t i o n Does your paper address subitem 1b-ii?
Copy and paste relevant sections from the manuscript abstract (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study Information about the level of human involvement are in the published protocol ( Copy and paste relevant sections from the manuscript abstract (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "The RCT found implementation effectiveness of digital peer support training-specifically, befrienders' peer support responses demonstrating significantly higher post-than pretraining scores in selfhood. The digital peer support intervention indicated feasibility and acceptability as an ongoing mechanism of support. The intervention demonstrated clinical effectiveness in enhancing selfhood, compassion and mindfulness, and in lowering depressive and anxiety symptoms among seekers in the intervention group at post intervention than seekers in the waitlist control group prior to intervention. The effect of the intervention on seekers' psychological well-being was sustained beyond the period of the intervention. The mechanism of change revealed that seekers' engagement of the intervention had both immediate and prospective implications for their psychological wellbeing." Your response is too large. Try shortening some answers.  Copy and paste relevant sections from the manuscript abstract (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study The trial outcome was positive (primary outcome was changed) Your response is too large. Try shortening some answers. Does your paper address CONSORT subitem 2b? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "This study had three primary aims. First, we evaluated the implementation effectiveness of (a) digital peer support training for emerging adults providing support (befrienders), (b) the intervention in offering an ongoing mechanism of support and (c) in identifying individuals with high risk of having a mental health condition. Second, we assessed the clinical outcomes of digital peer support training in terms of whether it (a) enhanced the four components of psychological well-being-specifically, mattering, self-hood, compassion and mindfulness and (b) improved the psychological well-being of emerging adults. Third, we investigated the mechanism of change linking digital peer support intervention to emerging adult psychological well-being." Does your paper address CONSORT subitem 3a? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "The Acceset platform incorporates digital features, such as emotion stamps, motivation Graphic Interface Format (GIF) emotionality, and functional adjustment stickers as markers of psychological well-being-specifically, emotionality (i.e., positivity and negativity), motivations, and functional adjustment (i.e., internalizing and externalizing behaviors), respectively. During the course of the digital peer support intervention, users' engagement with these features on the platform served as a source of self-report information on their psychological well-being status. The Acceset text-based peer disclosure process begins when seekers engage the platform to seek support with managing their emotional experiences. Details on the Acceset digital peer support training, the platform and the seeker-befriender interaction (peer support workflow) detailed in the protocol that outlined the RCT [30]." Your response is too large. Try shortening some answers.

4b-i) Report if outcomes were (self-)assessed through online questionnaires
Clearly report if outcomes were (self-)assessed through online questionnaires (as common in web-based trials) or otherwise.  5) The interventions for each group with sufficient details to allow replication, including how and when they were actually administered subitem not at all important 1 2 3 4 5 essential Does your paper address subitem 4b-ii?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study Not a required item because this did not bias results

5-i) Mention names, credential, affiliations of the developers, sponsors, and owners
Mention names, credential, a liations of the developers, sponsors, and owners [6] (if authors/evaluators are owners or developer of the software, this needs to be declared in a "Con ict of interest" section or mentioned elsewhere in the manuscript). Does your paper address subitem 5-i?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "MO is co-founder and chief executive officer of Acceset Pte. Ltd. DH is a scientific cofounder and shareholder of KYAN Therapeutics, which is developing digital medicine-based platforms to optimize cancer therapy. DH is also an inventor of pending patents pertaining to personalized medicine."

5-ii) Describe the history/development process
Describe the history/development process of the application and previous formative evaluations (e.g., focus groups, usability testing), as these will have an impact on adoption/use rates and help with interpreting results. Does your paper address subitem 5-ii?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study

5-iii) Revisions and updating
Revisions and updating. Clearly mention the date and/or version number of the application/intervention (and comparator, if applicable) evaluated, or describe whether the intervention underwent major changes during the evaluation process, or whether the development and/or content was "frozen" during the trial. Describe dynamic components such as news feeds or changing content which may have an impact on the replicability of the intervention (for unexpected events see item 3b). Does your paper address subitem 5-iii?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study Not applicable--the intervention did not undergo major changes during the evaluation process, neither did the development and/or content was "frozen" during the trial. No changes to dynamic components such as news feeds or changing content that may have an impact on the replicability of the intervention.

5-iv) Quality assurance methods
Provide information on quality assurance methods to ensure accuracy and quality of Does your paper address subitem 5-iv?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "Details on the trial following are listed in the published protocol that outlined the trial

5-vi) Digital preservation
Digital preservation: Provide the URL of the application, but as the intervention is likely to change or disappear over the course of the years; also make sure the intervention is archived (Internet Archive, webcitation.org, and/or publishing the source code or screenshots/videos alongside the article). As pages behind login screens cannot be archived, consider creating demo pages which are accessible without login.
C l e a r s e l e c t i o n Does your paper address subitem 5-vi?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study Acceset platform is publicly available and this Information is in the published protocol (

5-ix) Describe use parameters
Describe use parameters (e.g., intended "doses" and optimal timing for use

5-x) Clarify the level of human involvement
Clarify the level of human involvement (care providers or health professionals, also technical assistance) in the e-intervention or as co-intervention (detail number and expertise of professionals involved, if any, as well as "type of assistance offered, the timing and frequency of the support, how it is initiated, and the medium by which the assistance is delivered". It may be necessary to distinguish between the level of human involvement required for the trial, and the level of human involvement required for a routine application outside of a RCT setting (discuss under item 21 -generalizability).  Does your paper address CONSORT subitem 6a? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "Four Components of Psychological Well-Being (Mattering, Selfhood, Compassion and Mindfulness). For each letter exchange between befrienders and seekers, two undergraduate assistants extracted and coded the letter content on four components....All codes presented below were coded independently. Kappa coefficients ranged from .70 to .85, which indicated good inter-rater reliability." "Psychological Well-Being (Times 1-4). We created a latent construct with two indicatorsanxiety and depression. Befrienders and seekers provided self-report responses to the 7item General Anxiety Disorder Questionnaire (GAD-7) ....and the PHQ-9...All the items on the GAD-7 and PHQ-9 were rated on a 4-point scale ranging from 0 (not sure at all) to 4 (nearly every day)." Your response is too large. Try shortening some answers. 10) Who generated the random allocation sequence, who enrolled participants, and who assigned participants to interventions 11a) If done, who was blinded after assignment to interventions (for example, participants, care providers, those assessing outcomes) and how NPT: Whether or not administering co-interventions were blinded to group assignment Does your paper address CONSORT subitem 10? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study subitem not at all important 1 2 3 4 5 essential 11a-ii) Discuss e.g., whether participants knew which intervention was the "intervention of interest" and which one was the "comparator" Informed consent procedures (4a-ii) can create biases and certain expectations -discuss e.g., whether participants knew which intervention was the "intervention of interest" and which one was the "comparator".
C l e a r s e l e c t i o n Does your paper address subitem 11a-ii?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study Does your paper address CONSORT subitem 11b? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study This item is not applicable because this e-mental health trial as it refers to the intervention that both the intervention and wait-list control group were subjected to.
Does your paper address CONSORT subitem 12a? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "Main Analyses: Clinical Outcomes In addressing RQ2a and H2a, we examined if the Acceset peer support training of befrienders enhanced the four components of psychological well-being among seekers. We compared the change in mattering, self-hood, compassion and mindfulness scores of seekers over the course of the study. We conducted four sets of Latent Growth Curve Modelling (LCM) to examine the trajectories of mattering, selfhood, compassion, and mindfulness by fitting individual baseline growth models."

X26-iii) Safety and security procedures
Safety and security procedures, incl. privacy considerations, and any steps taken to reduce the likelihood or detection of harm (e.g., education and training, availability of a hotline) C l e a r s e l e c t i o n Does your paper address subitem X26-iii?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study 13a) For each group, the numbers of participants who were randomly assigned, received intended treatment, and were analysed for the primary outcome NPT: The number of care providers or centers performing the intervention in each group and the number of patients treated by each care provider in each center 13b) For each group, losses and exclusions after randomisation, together with reasons Does your paper address CONSORT subitem 13a? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "As for RQ2b and H2b, congruent with our hypothesis, engagement with Acceset digital peer support led to improved mental well-being of seekers in the intervention group, particularly lower psychological symptoms (post-intervention; M = 7.15, SE = 0.88) as compared to the waitlist control group (prior to intervention; M = 11.75, SE = 0.89), t(89) = 3.44, p = 0.0009." Your response is too large. Try shortening some answers. Does your paper address CONSORT subitem 13b? (NOTE: Preferably, this is shown in a CONSORT flow diagram) * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "At recruitment, we assessed the percentage of participants identified as being at an unacceptably high risk for depression and suicidality (i.e., meeting clinical cut-off of PHQ-9 > 9) and excluded them from the study. Our assessment found that seekers' (Mean = 5.89, SD = 3.69, range = 0 to 9) and befrienders' (Mean = 3.31, SD = 2.59, range = 0 to 8) depression score was below the cut-off at recruitment assessment (i.e., baseline prior to intervention). Thus, none of them were excluded from the study. During the course of the study, seekers' self-report at 3 weeks (conclusion of intervention) found that 9 of them had PHQ-9 > 9. 8 and 6 of them had scores above the clinical cut-off at 6 and 9 weeks (carry-over effect assessment), respectively. For befrienders, none of them met the clinical cut-off at 3, 6, and 9 weeks."

13b-i) Attrition diagram
Strongly recommended: An attrition diagram (e.g., proportion of participants still logging in or using the intervention/comparator in each group plotted over time, similar to a survival curve) or other gures or tables demonstrating usage/dose/engagement. Does your paper address subitem 13b-i?
Copy and paste relevant sections from the manuscript or cite the gure number if applicable (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "During the course of the study, seekers' self-report at 3 weeks (conclusion of intervention) found that 9 of them had PHQ-9 > 9. 8 and 6 of them had scores above the clinical cut-off at 6 and 9 weeks (carry-over effect assessment), respectively. For befrienders, none of them met the clinical cut-off at 3, 6, and 9 weeks. Seekers' self-report responses on the PHQ-9 functioned as the primary risk assessment for mental health conditions relating to depression and suicidality that was used to make referral to appropriate mental health support providers. These seekers were referred to appropriate mental health providers including counselling centers and hotlines within the NUS campus during the course of the study." Does your paper address CONSORT subitem 14a? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study Your response is too large. Try shortening some answers. 14a-i) Indicate if critical "secular events" fell into the study period Indicate if critical "secular events" fell into the study period, e.g., signi cant changes in Internet resources available or "changes in computer hardware or Internet delivery resources" C l e a r s e l e c t i o n Does your paper address subitem 14a-i?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study No critical "secular events" fell into the study period, e.g., significant changes in Internet resources available or "changes in computer hardware or Internet delivery resources" Your response is too large. Try shortening some answers. Does your paper address CONSORT subitem 15? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study " Table 1 and 2 present the descriptive statistics and correlations among variables for each letter exchange and at each time point, respectively. Among the four components of psychological well-being-mattering and selfhood displayed consistently moderate and positive associations, and similar associations were documented between compassion and mindfulness for both befrienders and seekers. For seekers, these four components and perceived social support had low to moderate negative associations with psychological symptoms at each time point (e.g., support and well-being at Time 1) and across time (support at Time1 and well-being at Time3)." Your response is too large. Try shortening some answers.

16-i) Report multiple "denominators" and provide definitions
Report multiple "denominators" and provide de nitions: Report N's (and effect sizes) "across a range of study participation [and use] thresholds" [1], e.g., N exposed, N consented, N used more than x times, N used more than y weeks, N participants "used" the intervention/comparator at speci c pre-de ned time points of interest (in absolute and relative numbers per group). Always clearly de ne "use" of the intervention. Does your paper address subitem 16-i? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "On average, the waiting period for seekers to receive a response was 10.27 hours (SD = 7.61), which was within 48 hours-the acceptable response period. Specifically, the seeker drop-out rate (from both the intervention and waitlist control arms) was 4% (4 out of 100 seekers) throughout the 3-week engagement with the Acceset intervention. In total, seekers, befrienders and moderators made a total of 653 visits on the study registration website and log-on events to the platform. In total, 104 seekers, 37 befrienders, and 2 moderators registered with Acceset for the study. A total of 192 letters were exchanged between seekers and befrienders (1 exchange comprised a letter that a seeker sent and a reply from a befriender) during the 3-week intervention for both the intervention and waitlist control arms. On average, 4.67 letters were exchanged per day for 21 days (3 weeks)."

16-ii) Primary analysis should be intent-to-treat
Primary analysis should be intent-to-treat, secondary analyses could include comparing only "users", with the appropriate caveats that this is no longer a randomized sample (see 18-i 17a) For each primary and secondary outcome, results for each group, and the estimated effect size and its precision (such as 95% confidence interval) Does your paper address subitem 16-ii?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "We assessed the sustained effect of the digital peer support beyond the period of the intervention by evaluating the change in mental well-being of the participants in both groups (intervention and control) after 3, 6 and 9 weeks from the baseline with self-report questionnaires. In conducting independent sample t-tests, we controlled for multiple comparisons with Bonferroni's post-hoc tests." Does your paper address CONSORT subitem 17a? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "In evaluating each model, we examined these fit indices: the χ² statistic, the root mean square error of approximation (RMSEA), the standardized root mean square residual (SRMR), and the comparative fit index (CFI subitem not at all important 1 2 3 4 5 essential 17a-i) Presentation of process outcomes such as metrics of use and intensity of use In addition to primary/secondary (clinical) outcomes, the presentation of process outcomes such as metrics of use and intensity of use (dose, exposure) and their operational de nitions is critical. This does not only refer to metrics of attrition (13-b) (often a binary variable), but also to more continuous exposure metrics such as "average session length". These must be accompanied by a technical description how a metric like a "session" is de ned (e.g., timeout after idle time) [ 17b) For binary outcomes, presentation of both absolute and relative effect sizes is recommended 18) Results of any other analyses performed, including subgroup analyses and adjusted analyses, distinguishing pre-specified from exploratory Does your paper address subitem 17a-i?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "On average, the waiting period for seekers to receive a response was 10.27 hours (SD = 7.61), which was within 48 hours-the acceptable response period. Specifically, the seeker drop-out rate (from both the intervention and waitlist control arms) was 4% (4 out of 100 seekers) throughout the 3-week engagement with the Acceset intervention. In total, seekers, befrienders and moderators made a total of 653 visits on the study registration website and log-on events to the platform. In total, 104 seekers, 37 befrienders, and 2 moderators registered with Acceset for the study. A total of 192 letters were exchanged between seekers and befrienders (1 exchange comprised a letter that a seeker sent and a reply from a befriender) during the 3-week intervention for both the intervention and waitlist control arms. On average, 4.67 letters were exchanged per day for 21 days (3 weeks)." Does your paper address CONSORT subitem 17b? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study Not applicable because there are no binary outcomes used in this study.
Your response is too large. Try shortening some answers. Does your paper address subitem 18-i?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study Not applicable because no subgroup analysis comparing only users (i.e., intervention group)was conducted.
""We assessed the sustained effect of the digital peer support beyond the period of the intervention by evaluating the change in mental well-being of the participants in both groups (intervention and control) after 3, 6 and 9 weeks from the baseline with self-report questionnaires. In conducting independent sample t-tests, we controlled for multiple comparisons with Bonferroni's post-hoc tests." Does your paper address CONSORT subitem 19? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "The study team informed the counselling center on the NUS campus and referred at-risk seekers for appropriate and timely support throughout the course of the intervention, as well as at week 6 and 9 follow up assessments on all seekers (to measure carryover effects) to ensure their psychological safety. As research on mental health intervention has noted, confidentiality can circumscribe post-referral processing and follow-up of referred participants as they might not be receptive or responsive to the referral [52]." Your response is too large. Try shortening some answers. Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "The study team informed the counselling center on the NUS campus and referred at-risk seekers for appropriate and timely support throughout the course of the intervention, as well as at week 6 and 9 follow up assessments on all seekers (to measure carryover effects) to ensure their psychological safety. As research on mental health intervention has noted, confidentiality can circumscribe post-referral processing and follow-up of referred participants as they might not be receptive or responsive to the referral [52]." Your response is too large. Try shortening some answers. Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study Focused-group discussions were conducted with moderators and befrienders on the use of Acceset platform.
Your response is too large. Try shortening some answers. 22-i) Restate study questions and summarize the answers suggested by the data, starting with primary outcomes and process outcomes (use) Restate study questions and summarize the answers suggested by the data, starting with primary outcomes and process outcomes (use).
C l e a r s e l e c t i o n Does your paper address subitem 22-i? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "This RCT assessed the implementation and clinical effectiveness of digital peer support intervention on emerging adults' psychological well-being. WOur findings provided evidence for H2b. Specifically, seekers in the intervention group had improved psychological wellbeing with lower symptoms of anxiety and depression at post intervention than seekers in the waitlist control group prior to intervention." Your response is too large. Try shortening some answers. Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study " Your response is too large. Try shortening some answers.

20-i) Typical limitations in ehealth trials
Typical limitations in ehealth trials: Participants in ehealth trials are rarely blinded. Ehealth trials often look at a multiplicity of outcomes, increasing risk for a Type I error. Discuss biases due to non-use of the intervention/usability issues, biases through informed consent procedures, unexpected events.
C l e a r s e l e c t i o n Does your paper address subitem 20-i? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "A possible limitation of this RCT on digital peer support intervention for emerging adult psychological well-being is the use of self-report measures for assessing clinical outcomes, which could be subjected to under-or over-estimation of anxiety and depressive symptoms. Another limitation is the preliminary results on validating the digital markers of psychological well-being on Acceset platform." Your response is too large. Try shortening some answers. Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "Notwithstanding these limitations, this study's development and validation of a novel digital innovation realize important contributions to the field of emerging adult mental health [25,31]. The key strengths of the proposed intervention are the scalability and sustainability of the digital peer support intervention." Your response is too large. Try shortening some answers. Discuss if there were elements in the RCT that would be different in a routine application setting (e.g., prompts/reminders, more human involvement, training sessions or other cointerventions) and what impact the omission of these elements could have on use, adoption, or outcomes if the intervention is applied outside of a RCT setting.
C l e a r s e l e c t i o n Does your paper address subitem 21-ii?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study "There are potential recommendations for future design and implementation of digital peer support for youth mental health, based on results from our RCT and those from a systematic review and meta-analysis of RCTs on the sustainable effects of mental health interventions for students from IHL [66-68]." Your response is too large. Try shortening some answers. About the CONSORT EHEALTH checklist X27-i) State the relation of the study team towards the system being evaluated In addition to the usual declaration of interests ( nancial or otherwise), also state the relation of the study team towards the system being evaluated, i.e., state if the authors/evaluators are distinct from or identical with the developers/sponsors of the intervention.
C l e a r s e l e c t i o n Does your paper address subitem X27-i?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie y explain why the item is not applicable/relevant for your study

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