Evaluating the Efficacy of a Social Media–Based Intervention (Warna-Warni Waktu) to Improve Body Image Among Young Indonesian Women: Parallel Randomized Controlled Trial

Background Body dissatisfaction is a global issue, particularly among adolescent girls and young women. Effective body image interventions exist but face barriers to scaling up, particularly in lower- and middle-income countries, such as Indonesia, where a need exists. Objective We aimed to evaluate the acceptability and efficacy of Warna-Warni Waktu, a social media–based, fictional 6-episode video series with self-guided web-based activities for improving body image among young Indonesian adolescent girls and young women. We hypothesized that Warna-Warni Waktu would increase trait body satisfaction and mood and decrease internalization of appearance ideals and skin shade dissatisfaction relative to the waitlist control condition. We also anticipated improvements in state body satisfaction and mood immediately following each video. Methods We conducted a web-based, 2-arm randomized controlled trial among 2000 adolescent girls and young women, aged 15 to 19 years, recruited via telephone by an Indonesian research agency. Block randomization (1:1 allocation) was performed. Participants and researchers were not concealed from the randomized arm. Participants completed self-report assessments of trait body satisfaction (primary outcome) and the internalization of appearance ideals, mood, and skin shade dissatisfaction at baseline (before randomization), time 2 (1 day after the intervention [T2]), and time 3 (1 month after the intervention [T3]). Participants also completed state body satisfaction and mood measures immediately before and after each video. Data were evaluated using linear mixed models with an intent-to-treat analysis. Intervention adherence was tracked. Acceptability data were collected. Results There were 1847 participants. Relative to the control condition (n=923), the intervention group (n=924) showed reduced internalization of appearance ideals at T2 (F1,1758=40.56, P<.001, partial η2=0.022) and T3 (F1,1782=54.03, P<.001, partial η2=0.03) and reduced skin shade dissatisfaction at T2 (F1,1744=8.05, P=.005, partial η2=0.005). Trait body satisfaction improvements occurred in the intervention group at T3 (F1, 1781=9.02, P=.005, partial η2=0.005), which was completely mediated by the internalization change scores between baseline and T2 (indirect effect: β=.03, 95% CI 0.017-0.041; direct effect: β=.03, P=.13), consistent with the Tripartite Influence Model of body dissatisfaction. Trait mood showed no significant effects. Dependent sample t tests (2-tailed) found each video improved state body satisfaction and mood. Cumulative analyses found significant and progressive improvements in pre- and poststate body satisfaction and mood. Intervention adherence was good; participants watched an average of 5.2 (SD 1.66) videos. Acceptability scores were high for understandability, enjoyment, age appropriateness, usefulness, and likelihood to recommend. Conclusions Warna-Warni Waktu is an effective eHealth intervention to reduce body dissatisfaction among Indonesian adolescent girls and young women. Although the effects were small, Warna-Warni Waktu is a scalable, cost-effective alternative to more intense interventions. Initially, dissemination through paid social media advertising will reach thousands of young Indonesian women. Trial Registration ClinicalTrials.gov NCT05383807, https://clinicaltrials.gov/ct2/show/NCT05383807 ; ISRCTN Registry ISRCTN35483207, https://www.isrctn.com/ISRCTN35483207 International Registered Report Identifier (IRRID) RR2-10.2196/33596

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. Manuscript tracking number * If this is a JMIR submission, please provide the manuscript tracking number under "other" (The ms tracking number can be found in the submission acknowledgement email, or when you login as author in JMIR. If the paper is already published in JMIR, then the ms tracking number is the four-digit number at the end of the DOI, to be found at the bottom of each published article in JMIR) 1a) Does your paper address CONSORT item 1a? * I.e does the title contain the phrase "Randomized Controlled Trial"? (if not, explain the reason under "other") https://docs.google.com/forms/d/e/1FAIpQLSfZBSUp1bwOc_OimqcS64RdfIAFvmrTSkZQL2-3O8O9hrL5Sw/viewform?pli=1&pli=1 13/92 subitem not at all important 1 2 3 4 5 essential 1a-i) Identify the mode of delivery in the title 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 "Social Media-Based Intervention"). Whilst the intervention is web-based, it will be limited to delivery on social media, thus it is important "social media" is used over other online descriptors.

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 Delivering the intervention on social media is key to our goal of large-scale dissemination; thus, the intervention does not contain non-web-based components.

1a-iii) Primary condition or target group in the title
Mention primary condition or target group in the title, if any (e.g., "for children with Type I Diabetes") Example: A Web-based and Mobile Intervention with Telephone Support for Children with Type I Diabetes: Randomized Controlled Trial C l e a r s e l e c t i o n 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 "Young Indonesian Women". Specifically, the intervention is aimed at "Indonesian women aged 15 to 19 years".

1b-i) Key features/functionalities/components of the intervention and comparator in the METHODS section of the ABSTRACT
Mention key features/functionalities/components of the intervention and comparator in the abstract. If possible, also mention theories and principles used for designing the site. Keep in mind the needs of systematic reviewers and indexers by including important synonyms. (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-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 "Social media-based, fictional six-episode video series supplemented with online activities.
(intervention vs waitlist control)." Content influenced by "Tripartite Influence Model of body dissatisfaction"

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 "a social media-based, fictional six-episode video series supplemented with self-guided online activities" 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 This is not a negative trial as the primary outcome of trait body satisfaction improved at follow-up (T3), relative to the control condition: "effective eHealth intervention to reduce body dissatisfaction among young Indonesian women." Does your paper address subitem 2a-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 "Body dissatisfaction among young women predicts negative mental and physical health consequences; shown to impact at least half of young Indonesian women; interventions typically rely on face-to-face provision, often in small group settings, led by professionals; Such an approach reduces the scalability of interventions due to costly nature coupled with a global shortage of mental health professionals; barriers are amplified in lower-and middle-income countries; The design of culturally specific interventions is critical; A viable solution to increase the scalability is the use of social media platforms; i.e., low cost, accessible, reduced social stigma, overcoming physical barriers to engagement; Warna-Warni Waktu is a stand-alone, social media-based intervention designed to reduce body dissatisfaction among young Indonesian women" 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 "Social media use has surged, with global usage among young people being almost ubiquitous. Social media-based interventions circumvent many barriers to accessing care in more traditional face-to-face methods by reducing costs and overreliance on mental health care, overcoming the need for physical proximity, and lessening the social stigma of participation given the relative anonymity afforded on social network sites. social mediabased interventions allow for targeting those in need within easily-accessed digital spaces typically visited daily, a crucially important consideration given high attrition rates often seen across other eHealth interventions; little research has examined the potential of using social media as a tool to disseminate interventions to reduce body dissatisfaction, despite promising findings from the broader field of mental health; waitlist control condition" METHODS 3a) Description of trial design (such as parallel, factorial) including allocation ratio 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 "(1) participants randomized to the intervention condition would experience increased trait body satisfaction and mood, and decreased internalization of appearance ideals and skin shade dissatisfaction at 1 day post-intervention, and 1 month follow-up, relative to the waitlist control condition; (2)  3b) Important changes to methods after trial commencement (such as eligibility criteria), with reasons 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 "A two-arm parallel randomized controlled web-based trial was conducted; Block randomization was performed with a 1:1 allocation with blocks of 4, 6, and 8." Does your paper address CONSORT subitem 3b? * 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 changes were made to the intervention or the trial design after trial commencement. subitem not at all important 1 2 3 4 5 essential Does your paper address subitem 4a-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 As the inclusion criteria stipulates that the participant must have her own mobile phone and be a daily user of Facebook or Instagram, internet literacy is implied. Therefore, it is not necessary to explicitly state the internet literacy is required.
4a-ii) Open vs. closed, web-based vs. face-to-face assessments: Open vs. closed, web-based vs. face-to-face assessments: Mention how participants were recruited (online vs. o ine), e.g., from an open access website or from a clinic, and clarify if this was a purely web-based trial, or there were face-to-face components (as part of the intervention or for assessment), i.e., to what degree got the study team to know the participant. In online-only trials, clarify if participants were quasi-anonymous and whether having multiple identities was possible or whether technical or logistical measures (e.g., cookies, email con rmation, phone calls) were used to detect/prevent these. Does your paper address subitem 4a-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 "A Jakarta-based research agency recruited young Indonesian women from ten cities across Indonesia offline; The agency recruited participants by phone via existing database of previous adult participants over the age of 40; Individuals who had a daughter between 15 and 17 years; Daughters were then screened by the recruiter. If she provided verbal assent to participate, parents again provided consent for their daughter's participation, this time via WhatsApp. A similar process was executed for eligible daughters of 18 or 19 years of age except they provided verbal and written consent themselves; Identities of parents and eligible daughters were confirmed on video calls via official photo-based IDs."

4a-iii) Information giving during recruitment
Information given during recruitment. Specify how participants were briefed for recruitment and in the informed consent procedures (e.g., publish the informed consent documentation as appendix, see also item X26), as this information may have an effect on user self-selection, user expectation and may also bias results. 4b) Settings and locations where the data were collected Does your paper address subitem 4a-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 "Parents who provided verbal consent supplied information about their socioeconomic status. If she provided verbal assent to participate, parents again provided consent for their daughter's participation via WhatsApp. A similar process was executed for eligible daughters of 18 or 19 years except they provided verbal and written consent. Identities of parents and eligible daughters were confirmed on video calls via official photo-based IDs." Information sheets were sent via WhatsApp.
Does your paper address CONSORT subitem 4b? * 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 Jakarta-based research agency recruited young Indonesian women from ten cities across the western, central, and eastern regions in Indonesia (Balikpapan, Bandung, Jakarta, Makassar, Manado, Medan, Palembang, Pontianak, Semarang, and Surabaya)"

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.
C l e a r s e l e c t i o n Does your paper address subitem 4b-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 "Participants completed online self-report questionnaires hosted on Qualtrics at baseline, 1 day following the intervention, and 1 month following the intervention"

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).
C l e a r s e l e c t i o n

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 "The intervention was a collaborative effort among the academic authors of this paper with Girl Effect, an international non-profit organization that creates empowering media content for girls; the Dove Self-Esteem Project, the social mission for Unilever's personal care brand, Dove; Percolate Galactic, an Indonesian creative agency focused on youth marketing; and young Indonesian women." "The intervention evaluated is owned by Girl Effect"

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.
C l e a r s e l e c t i o n

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 intervention development process (October 2019-May 2021) outlined in the protocol paper: www.researchprotocols.org/2022/1/e33596/ As detailed, six online focus groups of young women aged 15-19 years (N=36) were conducted to assess intervention acceptability and comprehension, revealing strong acceptability, comprehension, and enjoyment

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).
C l e a r s e l e c t i o n 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 "This stand-alone, self-guided intervention (Version 1), frozen during the trial"

5-iv) Quality assurance methods
Provide information on quality assurance methods to ensure accuracy and quality of information provided [1], if applicable.
C l e a r s e l e c t i o n 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

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

5-vii) Access
Access: Describe how participants accessed the application, in what setting/context, if they had to pay (or were paid) or not, whether they had to be a member of speci c group. If known, describe how participants obtained "access to the platform and Internet" [1]. To ensure access for editors/reviewers/readers, consider to provide a "backdoor" login account or demo mode for reviewers/readers to explore the application (also important for archiving purposes, see vi).
C l e a r s e l e c t i o n Does your paper address subitem 5-vii? * 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 research agency distributed data packages to cover internet costs. Participants randomized to the intervention condition were sent their PIN and a Qualtrics link with one video and its associated activities on Days 3-8. Included were state measures of body satisfaction and mood. Participants had 24 hours to engage with each link, with reminder messages sent to those who had not engaged with the intervention after 8 hours. Does your paper address subitem 5-viii? * 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 "Warna-Warni Waktu was informed by the Tripartite Influence Model; target friends, family, and the media, which influence the psychological processes of the internalization of appearance ideals and appearance-based social comparisons; these psychological processes directly through the delivery of media literacy education and by elucidating how appearance-based comparisons can lead to body dissatisfaction; the supplementary activities employ body image change techniques cognitive dissonance and psychoeducation" "key risk factors: social media and influencers (video 2), appearancebased comparisons (video 3), appearance-based teasing (video 4), and body talk (video 5)."

5-ix) Describe use parameters
Describe use parameters (e.g., intended "doses" and optimal timing for use). Clarify what instructions or recommendations were given to the user, e.g., regarding timing, frequency, heaviness of use, if any, or was the intervention used ad libitum.
C l e a r s e l e c t i o n Does your paper address subitem 5-ix?
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 "Participants randomized to the intervention condition were sent their PIN and a Qualtrics link with one video and its associated activities on Days 3-8; Participants had 24 hours to engage with each link (i.e., watch the video and completed its associated activities), with reminder messages sent to those who had not engaged with the intervention after 8 hours; Consists of six sequential short videos; Each of the videos and corresponding activities were embedded into six different Qualtrics questionnaires; participants were expected to engage with one video and its associated activities within 24 hours in the order received."

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).
C l e a r s e l e c t i o n Does your paper address subitem 5-x?
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 stand-alone, self-guided (i.e., no human involvement or assistance is required) intervention (Version 1)" 6b) Any changes to trial outcomes after the trial commenced, with reasons 7a) How sample size was determined NPT: When applicable, details of whether and how the clustering by care provides or centers was addressed Does your paper address subitem 6a-iii?
Copy and paste relevant sections from manuscript text "On Day 9, intervention participants received six self-report items at the end of the T2 questionnaire that assessed the intervention in relation to their overall enjoyment, the likability of the characters, understandability, age-appropriateness, usefulness, and the likelihood of recommending the intervention. Response options ranged from 1 (strongly disagree) to 5 (strongly agree)." Does your paper address CONSORT subitem 6b? * 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 changes to trial outcomes were made after the trial commenced. 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 "Similar RCTs assessing body dissatisfaction using the same outcome measure report a range of small to medium standardized effects sizes with Hedge's g ranging from 0.25 to 0.4 exceeding the minimum important clinical differences (MICD). To detect the MICD or larger, our proposed sample size of N=900 per group would provide in excess of 90% power (2-sided, α=.05) for between-group differences at either T2 or T3. This assumes that dropout does not exceed 20% in any one arm." Does your paper address CONSORT subitem 7b? * 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 Interim analyses; not a long-term RCT.
Does your paper address CONSORT subitem 8a? * 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 "automated, web-based randomizer (www.sealedenvelope.com/) to assign participants to the intervention or waitlist control group".
https://docs.google.com/forms/d/e/1FAIpQLSfZBSUp1bwOc_OimqcS64RdfIAFvmrTSkZQL2-3O8O9hrL5Sw/viewform?pli=1&pli=1 54/92 9) Mechanism used to implement the random allocation sequence (such as sequentially numbered containers), describing any steps taken to conceal the sequence until interventions were assigned Does your paper address CONSORT subitem 8b? * 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 "Block randomization was performed with a 1:1 allocation with blocks of 4, 6, and 8." Does your paper address CONSORT subitem 9? * 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 "After participants completed the baseline questionnaire, a researcher not involved in this project was concealed from participant information and condition and generated the allocation sequence (based on a block design) using an automated, web-based randomizer (https://www.sealedenvelope.com/) to assign participants to the intervention or waitlist control group." https://docs.google.com/forms/d/e/1FAIpQLSfZBSUp1bwOc_OimqcS64RdfIAFvmrTSkZQL2-3O8O9hrL5Sw/viewform?pli=1&pli=1 55/92 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 "Jakarta-based research agency recruited young Indonesian women; a researcher not involved in this project was concealed from participant information and condition and generated the allocation sequence; The day after completing the baseline questionnaire, intervention participants were told which group they were in by the research agency via WhatsApp. Those in the intervention condition were informed when to expect to receive the intervention; those in the control condition were informed they would receive a link to the second self-report assessment in a week's time"

11a-i) Specify who was blinded, and who wasn't
Specify who was blinded, and who wasn't. Usually, in web-based trials it is not possible to blind the participants [1, 3] (this should be clearly acknowledged), but it may be possible to blind outcome assessors, those doing data analysis or those administering cointerventions (if any).
C l e a r s e l e c t i o n Does your paper address subitem 11a-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 "The research agency was not concealed from the participant's randomized arm; to avoid interpretation bias, condition allocation was concealed from the data analyst throughout data preparation and trait outcome hypotheses testing. Concealment of condition allocation was not possible during state outcome hypotheses testing, due to the within-group design. The data analyst was provided with the state-based measures datafile only when analyses of the trait-based measures were complete." 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 "Allocation was shared with the research agency, who made participants aware which group they were in via WhatsApp the day after completing the baseline questionnaire. Those in the intervention condition were informed when to expect to receive the intervention; those in the control condition were informed they would receive a link to the second self-report assessment in a week's time.

12b) Methods for additional analyses, such as subgroup analyses and adjusted analyses
Does your paper address subitem 12a-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 "Independent sample t tests confirmed missing data for the primary outcome measure at T2 and T3 was not dependent on baseline values of trait body satisfaction; Chi-square analyses showed missing data at either T2 or T3 did not significantly differ between randomized arms; Analysis using Little's MCAR test indicated missingness was consistent with data being missing completely at random between T1 and T2 and between T1 and T3; Participants who failed to complete at least 80% of the items on a scale were omitted from the analyses for that scale. For hypothesis testing, the LMMs and post-hoc ANCOVAs were conducted on an ITT basis, without performing data imputation. As the percentage of missingness was below 5%, LMMs and ANCOVAs were considered robust against a noncomplete data set. Data imputation and per-protocol analyses were not conducted to avoid introducing bias" 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 "Parents provided verbal consent [by phone] then supplied their socioeconomic status. Daughters were screened by the recruiter to determine if she met inclusion criteria and exclusion criteria. If she provided verbal assent, parents once again provided consent for their daughter's participation, this time written via WhatsApp. A similar process was executed for eligible daughters of 18 or 19 years of age except they provided verbal and written consent for themselves."

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)

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 As detailed in our protocol paper, the parental and participant information sheets provided the benefits and risks of participating, in addition to details of two counseling services available to young women in Indonesia if they are experiencing any mental health concerns and require additional support. Further, information sheets contained the contact details of study author (BM) should they have any concerns relating to the execution of the study. 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 outlined in Figure 1, 2000 participants were recruited. 1855 were randomized with 932 in the intervention condition and 923 in the waitlist control. Of the intervention group, 924 participants' data were analyzed and of the waitlist control group, 923 participants' data were analyzed.
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 Figure 1 details the losses to both groups after randomization. 14a) Dates defining the periods of recruitment and follow-up 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 As this was a discrete intervention delivered over six days, we did not collect usage beyond that period. However, we have provided data of attrition in relation to viewing the videos and the completing the associated activities: ""Attrition rates were also low for state outcomes.
For the intervention group only, missing responses on one-item state measures ranged between 12.13% (112/924) (pre-video 1) and 13.85% (128/924) (post-video 6) for body satisfaction and between 10.86% (111/924) (pre-video 1) and 13.97% (129/924) (post-video 6) for mood (Multimedia Appendix 5)." Multimedia Appendix 5 details the "retention rates for state outcomes in the intervention group". subitem not at all important 1 2 3 4 5 essential 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 "Recruitment for the pilot study was conducted from September 13 to 16, 2021, and executed between September 18 and 26, 2021." Main trial "Recruitment took place between October 12 and November 5, 2021. The main trial was executed from November 6 to December 12, 2021."

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"

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 secular events occurred during the trial period.
Does your paper address CONSORT subitem 14b? * 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 trial was executed as planned. It did not end early. subitem not at all important 1 2 3 4 5 essential 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 Does your paper address subitem 15-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 Demographics related to age and socioeconomic status are outlined in Table 1. "Young women were invited to participate if they had their own mobile phone, and visited Facebook or Instagram daily."

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 "The trait outcomes data set across conditions had 0.33% missing item responses at T1, 4.61% at T2, and 3.34% at T3. Independent sample t tests confirmed missing data for the primary outcome at T2 and T3 was not dependent on baseline values of trait body satisfaction (t1845=.93, P(two-sided)=.35 at T2; t1845=1.0, P=.32 at T3). Chi-square analyses showed missing data at either T2 or T3 did not significantly differ between randomized arms (χ21:=3.48, P(two-sided)=.06). Analysis using Little's MCAR test indicated that data were missing completely at random both between T1 and T2 (χ21:=0.87, P(twosided)=.35) and between T1 and T3 (χ21:=1.0, P(two-sided)=.31). Participants who did not complete 80% of the items on a given scale were omitted from the analyses for that scale.
As the percentage of missingness was below 5%, the LMMs and post-hoc ANCOVAs were conducted on an ITT basis."

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 "The effect of the intervention on trait outcomes was examined by running four Linear Mixed Models (LMM) on an intention-to-treat (ITT) basis, with baseline measures at T1 as a covariate, randomized group as a two-level between-subjects factor, study phase (T2, T3) as a two-level repeated measures factor, an unstructured covariance matrix, and Restricted Maximum Likelihood estimation method. The statistical model was hierarchically balanced, with one three-way interaction between covariate, phase, and randomized group; three twoway interactions (covariate*phase; covariate*randomized group; phase*randomized group); and three main effects (covariate, phase, and randomized group

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) [1] (report under item 6a).
C l e a r s e l e c t i o n 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 "Intervention adherence metrics were collected. On average, intervention participants watched 5 out of the 6 videos and completed 14 out of the 18 activities. See Multimedia Appendix 6 for the adherence for each video and activity. It was not possible to accurately calculate the average amount of time that intervention participants engaged with the entire intervention as time spent on the intervention for each of the six videos for many participants (n=401) exceeded an hour, suggesting that participants did not close the survey tab after watching the video and completing the corresponding activities." 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 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 The RCT did not include binary outcomes.

18-i) Subgroup analysis of comparing only users
A subgroup analysis of comparing only users is not uncommon in ehealth trials, but if done, it must be stressed that this is a self-selected sample and no longer an unbiased sample from a randomized trial (see 16-iii 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 We did not perform sub-group analysis within the intervention group. Looking at analyses performed within the intervention group only, we ran some cumulative analysis on state outcomes and an exploratory mediation analysis on the primary outcome. Since both aforementioned tests included all the participants randomized in the intervention conditions, these cannot be classified as sub-group analyses.
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 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 "funding constraints prevented us from evaluating the independent impact of the intervention's videos vs the combined impact of the videos and activities. Although social comparisons are a potentially important change mechanism in this work as per the Tripartite Influence Model, no relevant measures exist that have been validated among Indonesian adolescents/young adults. It would be advantageous for an appropriate measure to be validated in the Indonesian context and incorporated into a replication study. Despite accurately reproducing the intervention's activities as they would be presented on social media so as to collect adherence data, our study lacks ecological validity supporting the future evaluation of it in the environment it will be delivered"

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 To limit the impact of Type I error, we defined a primary outcome a-priori, and limited the inclusion of secondary outcomes to only three scales. Given the presence of only one primary outcome, the analyses did not require adjustment for multiple testing. a significance level of p<.05 was set for all outcome measures. "A power calculation showed that considering the total sample of 1,847 participants, three time points, five outcomes, and a correlation among repeated measurements ranging between r=0.5 and r=0.8, we achieved a power ranging between 99% and 100% to detect small and medium effect sizes, considering a .05 α error. The analyses were adequately powered." 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 "our study lacks ecological validity as we did not evaluate Warna-Warni Waktu on the social media platforms where it will be disseminated." 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 "prompts will not be used or available when the intervention is disseminated on social media" https://docs.google.com/forms/d/e/1FAIpQLSfZBSUp1bwOc_OimqcS64RdfIAFvmrTSkZQL2-3O8O9hrL5Sw/viewform?pli=1&pli=1 89/92

X27) Conflicts of Interest (not a CONSORT item)
subitem not at all important 1 2 3 4 5 essential Does your paper address CONSORT subitem 25? * 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 "research grant from the Dove Self-Esteem Project"

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. 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 Girl Effect owns the intervention.
As a result of using this checklist, did you make changes in your manuscript? * What were the most important changes you made as a result of using this checklist?
information related to the CHERRIES checklist STOP -Save this form as PDF before you click submit To generate a record that you lled in this form, we recommend to generate a PDF of this page (on a Mac, simply select "print" and then select "print as PDF") before you submit it.
When you submit your (revised) paper to JMIR, please upload the PDF as supplementary le.
Don't worry if some text in the textboxes is cut off, as we still have the complete information in our database. Thank you!