The AYA Oncology Self-care Movement

For adolescents and young adults (AYAs) who meet inclusion criteria, trained staff will introduce the study and confirm eligibility using a standardized checklist. For AYAs \<18 years old, we will conduct enrollment with AYAs and their parent/legal guardian together, as we have successfully done before.

After study procedures are thoroughly explained and questions are answered, informed written eConsent and eAssent (AYAs \<18) will be obtained. Across aims, AYAs will then complete a baseline questionnaire (assessing demographics, cancer information, and perceived medication adherence and self-management abilities). Electronic health record (EHR) review will also occur, with release forms obtained for AYAs outside our centers.

Trial data collection will occur over 6-months. All enrolled AYAs will complete baseline (T1) measures (\~20 minutes) online via REDCap. All enrolled participants will be provided with and receive a tutorial on a validated electronic adherence monitor, which they will be instructed to use to monitor daily 6-MP adherence for the entire 6-month study period. For 28-days (i.e., the typical time between follow-up visits), all enrolled AYAs (both groups) will complete a run-in period involving electronic monitoring of 6-MP adherence only (no intervention) to calculate baseline adherence rates. On day 29, AYAs will complete a checklist about their usage of the electronic pill bottle (to problem-solve any barriers prior to randomization) and then be randomized to the #AYAOSM social media intervention or no message control.

Participants in both groups will be asked to continue using the electronic pill bottle to passively monitor 6-MP adherence over the next five months. Participants in both groups will also be provided with an educational website describing basic information about 6-MP.

#AYAOSM Intervention Group. For AYAs randomized to the social media condition, the intervention will begin on day 29 and last for 12 weeks. Across the 12-week intervention period, AYAs will receive \~2-3 distinct social media messages per week. Messages will be delivered using direct messaging to the participant's own social media account (e.g., TikTok or Instagram), from a study-created social media account.

Control Condition. AYAs who are randomized to the control will only receive the educational website and continue to monitor their 6-MP adherence electronically. They will not receive any of the social media messages during the 6-month period.

Following the intervention period, all participants will be asked to complete follow-up REDCap surveys of self-management variables at 4-months (T2) and 6-months (T3). In addition to self-management indices, AYAs from the social media group will complete a questionnaire measure of intervention acceptability at T2. Some AYAs will also be asked to complete an interview about their experiences with the intervention. Electronic pill bottles will be returned to the study team to download data at T3.

• Medication Adherence Measure (4 items) [Time frame: 6-months]
• PROMIS Self-Efficacy for Managing Chronic Conditions - Managing Medications and Treatment - Short Form (8 items) [Time frame: 6-months]
• Theory of Planned Behavior Questionnaire (3 items) [Time frame: 6-months]
• PROMIS Emotional Support and Information Support - Short Forms (8 items each) [Time frame: 6-months]
• Objective engagement with social media intervention [Time frame: 12-week intervention period]
• Implementation barriers and facilitators [Time frame: 6-months]