A Web-Based Intervention to Improve Health Literacy and Obesogenic Behaviors Among Adolescents: Protocol of a Randomized Pilot Feasibility Study for a Parallel Randomized Controlled Trial

Background Predictive theoretical models suggest that health knowledge works in conjunction with motivation and behavioral skills to influence adolescents’ obesogenic behavior. However, most of the existing adolescent interventions target these variables in isolation. Furthermore, health literacy (HL), a precursor to health knowledge, is necessary for translating health knowledge into behavior and is negatively related to adolescents’ obesity status. However, HL has not been included in obesity interventions targeting adolescents. Objective This study aims to pilot the feasibility of a 2-armed web-based obesity prevention intervention in school settings and assess the preliminary effectiveness of adding an HL module to an obesity prevention intervention for adolescents. Methods This web-based pilot feasibility study will take place in the Northeastern United States. Participants will be adolescents (aged 13-16 years) attending school, and recruitment will be conducted through flyers to parents and adolescents in participating classes or advisory groups at the school. The intervention includes 2 arms: an experimental arm that will receive an HL module and 3 obesity prevention modules and a comparison arm that will receive a vaping module and 3 obesity prevention modules. A blinded randomized procedure will be used to allocate classrooms and advisory groups to the experimental and comparison arms. The intervention will be fully web-based. Participants will complete measures of their HL and obesogenic behavior–related health knowledge, motivation, and behaviors at 3 time points (baseline, 1 month after the intervention, and 3 months after the intervention) via web-based surveys. The primary outcomes will be the measures of study feasibility (recruitment, retention, completion, and treatment fidelity rates). Secondary outcomes will be preliminary efficacy, as measured by logistic and linear regressions and calculation of effect sizes. Descriptive statistics will be calculated for all measures at each time point. Results This study was approved by the City University of New York Institutional Review Board in August 2020. As of June 2022, the web-based intervention design is complete and ready for use. Recruitment, data collection, and intervention implementation are scheduled to begin in September 2022. These results are expected to be published in 2023. Conclusions This study’s feasibility findings will inform changes to the intervention content and randomized controlled trial design. The study’s efficacy findings will inform the sample size for the full-scale randomized controlled trial and the preliminary utility of the intervention. Trial Registration ClinicalTrials.gov NCT04252677; https://clinicaltrials.gov/ct2/show/NCT04252677 International Registered Report Identifier (IRRID) PRR1-10.2196/40191

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 / scientific 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. yes: all primary outcomes were significantly better in intervention group vs control partly: SOME primary outcomes were significantly better in intervention group vs control no statistically significant difference between control and intervention potentially harmful: control was significantly better than intervention in one or more outcomes inconclusive: more research is needed Other: not submitted yet -in early draft status not submitted yet -in late draft status, just before submission submitted to a journal but not reviewed yet submitted to a journal and after receiving initial reviewer comments submitted to a journal and accepted, but not published yet published Other: not submitted yet / unclear where I will submit this 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 offline 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.  T  R  A  C  T  :  S  t  r  u  c  t  u  r  e  d  s  u  m  m  a  r  y  o  f  t  r  i  a  l  d  e  s  i  g  n  ,  m  e  t  h  o  d  s  ,  r  e  s  u  l  t  s  ,  a  n  d  c  o  n  c  l  u  s  i  o  n  s   N  P  T  e  x  t  e  n  s  i  o  n  :  D  e  s  c  r  i  p  t  i  o  n  o  f  e  x  p  e  r  i  m  e  n  t  a  l  t  r  e  a  t  m  e  n  t  ,  c  o  m  p  a  r  a  t  o  r  ,  c  a  r  e  p  r  o  v  i  d  e  r  s  ,  c  e  n  t  e  r  s  ,  a  n  d  b  l  i  n  d  i  n  g  s  t  a  t  u  s  . subitem not at all important 1 2 3 4 5 essential subitem not at all important e  a  t  u  r  e  s  /  f  u  n  c  t  i  o  n  a  l  i  t  i  e  s  /  c  o  m  p  o  n  e  n  t  s  o  f  t  h  e  i  n  t  e  r  v  e  n  t  i  o  n  a  n  d  c  o  m  p  a  r  a  t  o  r  i  n  t  h  e  M  E  T  H  O  D  S  s  e  c  t  i  o  n  o  f  t  h  e  A  B  S  T  R  A  C  T 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. 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 briefly explain why the item is not applicable/relevant for your study "Participants will complete measures of their HL and obesogenic behaviors-related health knowledge, motivation, and behaviors at three time points (baseline, 1 month postintervention, 3 months post-intervention) via online surveys. " subitem not at all important Conclusions/Discussions in abstract for negative trials: Discuss the primary outcome -if the trial is negative (primary outcome not changed), and the intervention was not used, discuss whether negative results are attributable to lack of uptake and discuss reasons. 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 briefly explain why the item is not applicable/relevant for your study "The main study goal is to develop and preliminarily evaluate a digital obesity prevention intervention with and without health literacy for adolescents. This study distinguishes between HL and health knowledge -these two concepts tend to be inaccurately substituted in some research literature. However, HL is a precursor to health knowledge [32], that is, HL is the skills needed to access, understand, and utilize health information for a specific behavior. Despite this, HL is understudied and rarely addressed in health behavior interventions. This study seeks to fill this gap. Aim 1 of this study is to modify and use successful components of existing obesity interventions into an interactive digital platform with an added-on HL component. Aim 2 of this study is a two-arm randomized clinical trial of the adapted digital obesity prevention intervention for adolescents with and without a HL component. The purpose of this pilot RCT is to determine the feasibility and preliminary effectiveness of the intervention to inform the full scale RCT. Specifically, the primary objectives of this study are to (1) assess the acceptability of the intervention for adolescents; (2) determine the elements of the intervention with the highest adolescent engagement; and (3) determine the suitability and appropriateness of the intervention modality and implementation for school settings by examining the recruitment, retention, completion, and fidelity rates. The secondary objectives of the study are to measure the preliminary efficacy of the intervention to improve obesogenic behaviors and HL and to collect data to calculate effect sizes and power analyses to inform the sample size needed for the full scale RCT to be able to determine if adding a HL component to an obesity prevention intervention improves adolescents' obesity prevention behaviors more than an obesity prevention intervention alone. " 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 briefly explain why the item is not applicable/relevant for your study "Children and adolescents are increasingly experiencing obesity-related "chronic degenerative diseases" that were once categorized as adult health problems  [15]. The school-based New Moves intervention aimed to improve adolescents' diet-and PA-related knowledge, attitudes, beliefs, skills, and selfefficacy as well as provide strategies for improving social support [17,21]. The communitybased Go Girls! intervention aimed to improve knowledge, self-efficacy, social support, motivation, and behavioral skills for healthy eating and physical activity [16]. The schoolbased DOiT intervention aimed to increase adolescents' knowledge, awareness, behavioral skills, social support, habits, and self-efficacy regarding energy intake and output [15,22]. All three studies reported significant improvements in obesogenic-related behaviors post intervention.
These studies included activities that can be adapted for a digital platform and provide a strong basis for our intervention. However, similar to other adolescent obesity prevention interventions, the New Moves, Go Girls! and DOiT interventions do not include building adolescents' general skills for transferring knowledge into behavior (i.e., health literacy [HL] 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 briefly explain why the item is not applicable/relevant for your study "This study distinguishes between HL and health knowledge -these two concepts tend to be inaccurately substituted in some research literature. However, HL is a precursor to health knowledge [32], that is, HL is the skills needed to access, understand, and utilize health information for a specific behavior. Despite this, HL is understudied and rarely addressed in health behavior interventions. This study seeks to fill this gap. Aim 1 of this study is to modify and use successful components of existing obesity interventions into an interactive digital platform with an added-on HL component. Aim 2 of this study is a two-arm randomized clinical trial of the adapted digital obesity prevention intervention for adolescents with and without a HL component. The purpose of this pilot RCT is to determine the feasibility and preliminary effectiveness of the intervention to inform the full scale RCT. Specifically, the primary objectives of this study are to (1) assess the acceptability of the intervention for adolescents; (2) determine the elements of the intervention with the highest adolescent engagement; and (3) determine the suitability and appropriateness of the intervention modality and implementation for school settings by examining the recruitment, retention, completion, and fidelity rates. The secondary objectives of the study are to measure the preliminary efficacy of the intervention to improve obesogenic behaviors and HL and to collect data to calculate effect sizes and power analyses to inform the sample size needed for the full scale RCT to be able to determine if adding a HL component to an obesity prevention intervention improves adolescents' obesity prevention behaviors more than an obesity prevention intervention alone." 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 briefly 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 briefly explain why the item is not applicable/relevant for your study This is not applicable, study has not started.
Bug fixes, Downtimes, Content Changes: ehealth systems are often dynamic systems. A description of changes to methods therefore also includes important changes made on the intervention or comparator during the trial (e.g., major bug fixes or changes in the functionality or content) (5-iii) and other "unexpected events" that may have influenced study design such as staff changes, system failures/downtimes, etc.
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 briefly explain why the item is not applicable/relevant for your study This is not applicable, study has not started.
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 briefly explain why the item is not applicable/relevant for your study "Seventy-six adolescents between 13 and 16-years-old who attend high school in Boston, Massachusetts will be recruited for the study. The other inclusionary criterion is parental permission for participation. Adolescents who are already participating in interventions related to healthy eating, physical activity, and/or obesity prevention or treatment or who have medical conditions that prevent them from engaging in physical activity or requires they adhere to extremely restricted diets (e.g., ketogenic diet) will be excluded from the 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 briefly explain why the item is not applicable/relevant for your study This is not included because the intervention is in the context of a classroom where compute use is part of their daily routine a c e a s s e s s m e n t s : Open vs. closed, web-based vs. face-to-face assessments: Mention how participants were recruited (online vs. offline), e.g., from an open access website or from a clinic, and clarify if this was a purely webbased 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 confirmation, phone calls) were used to detect/prevent these.
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. 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 briefly explain why the item is not applicable/relevant for your study "For the first phase of recruitment, school administrators will give study flyers to students and email the study flyer to parents of students in participating classes. The emailed flyer will include a Qualtrics link for parents to access the parent permission form and a brief demographic survey. The class or advisory group with the highest returned parent forms rate (regardless of whether permission was granted or denied) will receive a class prize (e.g., donation to class field trip fund) at the end of the first 2 weeks of the recruitment period. Characteristics of enrolled participants will be monitored to determine progress on recruiting the desired sample with regards to sex and racial and ethnic minority status. At the two-week time point during Phase 1 recruitment, the second phase of recruitment will be initiated in an attempt to achieve the desired sample. In Phase 2, adolescents whose parents did not complete the permission form online will be given a study flyer with a QR code for parents to access the Qualtrics link. A paper permission form and demographic survey will also be attached to the flyer. At each phase of recruitment, teachers will also make announcements about the study in class encouraging students to have their parents complete the permission forms. Recruitment will end 2 weeks after the initiation of Phase 2 recruitment. The class with the highest increase in returned consent forms at the end of the 2nd phase of recruitment will be incentivized with a class prize (e.g., donation to their class trip/dance). Phase 1 recruitment strategy is ongoing throughout the 4 weeks of recruitment as parents will be sent weekly reminder emails to complete the permission form and demographic survey. These procedures are consistent with several national studies (e.g., National Survey of Family Growth [35,36], National Survey of College Graduates [37]). Active monitoring of participant enrollment will occur throughout the four weeks of study recruitment and enrollment. To ensure participation is voluntary and not coerced, incentives are attached to consent form return rather than study enrollment. All recruitment and consent materials will be available in English, Spanish, and Haitian Creole to accommodate Haitian Creole-and Spanish-speaking parents with limited English language proficiency. Adolescent assent will be obtained prior to data collection. Note that parent permission and adolescent assent is specific to data collection related to the 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 briefly explain why the item is not applicable/relevant for your study "Seventy-six adolescents between 13 and 16-years-old who attend high school in Boston, Massachusetts will be recruited for the 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 briefly explain why the item is not applicable/relevant for your study "Data collection will be completed online via the Qualtrics survey platform. After a team member verbally explains the assent form, adolescents will be provided with a link where the first page will include the written assent form. After providing assent, adolescents will be routed to the survey." 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 briefly explain why the item is not applicable/relevant for your study "Regarding specific content, initial focus groups with adolescents informed the initial content of the HL modules while prior obesity prevention intervention studies informed the content for the obesity prevention modules. In a pre-intervention development study by the author, adolescents participated in multiple focus groups where they described how they view HL, how they knew they were using HL, and what type of HL skills they felt they lacked [30,31] Regarding acceptability and usability, adolescents' participated in cognitive interviews while completing the HL and Behavior Skills modules. This was done prior to the building out of the other modules of the intervention. The feedback provided on the HL and Behavior Skills modules was used to revise those modules and applied to the development of the remaining intervention modules." 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 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 briefly explain why the item is not applicable/relevant for your study This is not included. This is a pilot and this process will be done after any changes prior to the full scale RCT . The IMBM includes three critical determinants of performance of health behaviors: healthrelated information (facts, beliefs), motivation (personal attitudes, social support) and behavioral skills (objective skills and confidence for performing the behavior). Information and motivation support behavioral skills to influence behavior ( Figure 2, arrows a-c). However, information and motivation may directly impact behavior when only basic skills are needed (Figure 1, arrows d-e). Health behaviors ultimately predict health outcomes ( Figure  2, arrow f).
The relational developmental systems framework was used to determine what variables were explored in the IMBM. Given that the health-related information and behavioral skills constructs in the IMBM are specific to the health behavior, and that HL is a precursor to health knowledge32, and likely independently influences motivation, behavioral skills, and behavior, HL was included as a separate construct in the model (dashed lines in Figure 2). We expect HL to directly predict information, motivation, behavioral skills, and health behaviors ( Figure 2, arrows g-j), and indirectly predict health behaviors through information (g → d, g → a → c), motivation (j → e, j → b → c), and behavioral skills (i → c). Therefore, improvements are expected in the experimental condition on all variables in the model compared to the comparison group." See 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 briefly explain why the item is not applicable/relevant for your study "Adolescents will complete one lesson per homeroom or advisory period with 1-2 lessons per week depending on their class schedule." 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). 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 briefly explain why the item is not applicable/relevant for your study "The intervention will be provided in lieu of class activities and will be solely online. Specifically, teachers will only be involved in instructing adolescents to login to the webbased platform but all other activities of the intervention will occur via the web-based platform." 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 briefly explain why the item is not applicable/relevant for your study "The intervention will be provided in lieu of class activities and will be solely online.
Specifically, teachers will only be involved in instructing adolescents to login to the webbased platform but all other activities of the intervention will occur via the web-based platform."

-
Describe any co-interventions (incl. training/support): Clearly state any interventions that are provided in addition to the targeted eHealth intervention, as ehealth intervention may not be designed as stand-alone intervention. This includes training sessions and support [1]. It may be necessary to distinguish between the level of training required for the trial, and the level of training for a routine application outside of a RCT setting (discuss under item 21 -generalizability. Copy and paste relevant sections from manuscript text "Treatment fidelity will be assessed using web analytics data gathered during the intervention. Median time spent on each intervention task will be calculated and participants who spent less than three median absolute deviations below the median will be assumed to have not engaged with the content enough to be fully exposed to the treatment. Treatment fidelity percentages will be calculated based on users meeting the a priori thresholds." 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 briefly explain why the item is not applicable/relevant for your study "The sample size was based on power calculations computed using preliminary data. Preliminary data suggest that a sample 60 participants with 30 per group would be sufficient. We plan on enrolling and randomizing 76 participants to allow for a 20% dropout at 3-month follow-up. The sample size is sufficient to calculate feasibility metrics, preliminary efficacy, and inform future power calculations for the more complexed fullscaled RCT. " 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 briefly explain why the item is not applicable/relevant for your study "Specifically, a blinded research team member who is not involved in providing assent and who has no knowledge of the students in the classes/ advisory groups will assign each classroom/advisory group a number from 1 to 4 then a computerized random number generator will be used to assign the classroom/advisory group to the conditions. "  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 briefly explain why the item is not applicable/relevant for your study "Specifically, a blinded research team member who is not involved in providing assent and who has no knowledge of the students in the classes/ advisory groups will assign each classroom/advisory group a number from 1 to 4 then a computerized random number generator will be used to assign the classroom/advisory group to the conditions. " ? * 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 briefly explain why the item is not applicable/relevant for your study "a blinded research team member who is not involved in providing assent and who has no knowledge of the students in the classes/ advisory groups" 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". 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 briefly explain why the item is not applicable/relevant for your study This is not relevant. There were 2 study conditions and they were analyzed as such.
Imputation techniques to deal with attrition / missing values: Not all participants will use the intervention/comparator as intended and attrition is typically high in ehealth trials. Specify how participants who did not use the application or dropped out from the trial were treated in the statistical analysis (a complete case analysis is strongly discouraged, and simple imputation techniques such as LOCF may also be problematic [4] 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 briefly explain why the item is not applicable/relevant for your study "For each outcome, we will also analyze the time points together in the same model, using linear and logistic mixed effects models with random subject-specific intercepts and slopes. This will permit analysis of all participants, including those who drop out. Mixed models can accommodate missingness at random." 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 briefly explain why the item is not applicable/relevant for your study This is a pilot RCT and is not powered to conduct subgroup analyses 6/20/22, 9:19 AM CONSORT-EHEALTH (V 1.6.1) - 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 briefly explain why the item is not applicable/relevant for your study "All study procedures are approved by the City University of New York Institutional Review Board (2020-0575-PHHP) and will be carried out in accordance with what is outlined in the approved application. Data will only be used from participants with signed parent permission forms and who assent to participate. " 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 briefly explain why the item is not applicable/relevant for your study "The emailed flyer will include a Qualtrics link for parents to access the online parent permission form and a brief demographic survey. Parents will select 'yes' or 'no' to indicate if they agree for their adolescent to participate in the study. " "A paper permission form, demographic survey, and empty envelope will also be attached to the flyer. Parents who complete the paper permission form will be asked to put it in the envelope, seal the envelope, and have their adolescent return the envelope to their teacher." "Adolescent assent will be obtained online prior to data collection as the first page of the online survey. Adolescents who select 'no' to assent will be exited out of the survey and those who select 'yes' will be able to see the survey." 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 briefly explain why the item is not applicable/relevant for your study "The intervention website includes a contact us button so that students may report any concerns or comment. This will be closely monitored by research staff and staff will work to resolve issues as quickly as possible. "   D  o  e  s  y  o  u  r  p  a  p  e  r  a  d  d  r  e  s  s  C  O  N  S  O  R  T  s  u  b  i  t  e  m  1  3  a ? * 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 briefly explain why the item is not applicable/relevant for your study The study has not been done yet, therefore this is not applicable.
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 figures or tables demonstrating usage/dose/engagement. 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 briefly explain why the item is not applicable/relevant for your study The study has not been done yet, therefore this is not applicable. Report multiple "denominators" and provide definitions: 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 specific pre-defined time points of interest (in absolute and relative numbers per group). Always clearly define "use" 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 briefly explain why the item is not applicable/relevant for your study The study has not been done yet, therefore this is not applicable.
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). 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 definitions 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 defined (e.g., timeout after idle time) [1] (report under item 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 briefly explain why the item is not applicable/relevant for your study The study has not been done yet, therefore this is not applicable. 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 briefly explain why the item is not applicable/relevant for your study The study has not been done yet, therefore this is not applicable.
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. The study has not been done yet, therefore only a few limitations can be discerned. " However, the small sample means preliminary efficacy is mostly useful for calculating RCT sample needs rather than making strong inferences about the utility of the intervention. Another limitation of the study is the use of schools. Schools are an isolated portion of the adolescent population as it excludes adolescents who may be home-schooled or out of school for other reasons. These excluded adolescents may have different HL and health behavior change needs and access to resources so the efficacy and effectiveness of the intervention for these adolescents cannot be determined from this study. Further, it is not possible to implement blinding. This may impact results as adolescents in different conditions may discuss and compare what they are doing in their conditions and this can lead to information seeking that conflates the findings. " 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 briefly explain why the item is not applicable/relevant for your study This is critical as interventions using digital platforms extend the reach and use of the intervention modules as geography, personnel, and time constraints minimally impact implementation. 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 briefly explain why the item is not applicable/relevant for your study This project is funded by the NIH (grant #: 1R21DK117345, 1K12HD092535, L30DK126209). The funders had no influence on the content of the intervention and will not have influence on the interpretation of the results.