ETSF for Latinx Young Adults with Alcohol Use Disorder

Recruitment feasibility will be measured by the number of participants screened and enrolled each month.

Randomization feasibility will be measured by the number of baseline demographic variables with statistically significant group differences.

Retention/attrition feasibility will be measured by retention rates in each condition.

Adherence feasibility will be measured by the percentage of eTSF app components used by the eTSF condition participants.

Assessment feasibility will be measured by the proportion of missing data in each assessment.

Intervention credibility will be measured using a single-item question: "On a scale from 1 to 5, where 1 indicates 'not at all' and 5 indicates 'very much,' to what extent do you believe this treatment will be beneficial for you?" Only eTSF condition participants will receive this measure.

Intervention satisfaction will be measured using the mHealth Satisfaction Questionnaire, which has a total score range from 14 to 42. Higher total scores indicate greater user satisfaction with the mHealth app.

Acceptability will be measured using the Abbreviated Acceptability Rating Profile, which scores range from 8 to 48. Higher scores indicate greater acceptability of the intervention.

Intervention engagement will be automatically recorded by the app during the study period and be measured in terms of app opening frequency, time spent on the app per use session (i.e., the time between opening and closing the app), most frequently used intervention component, time spent per intervention component, the completion rate of each selected component, reports of technical problems.

Alcohol use will be measured using the Time-Line Follow-Back (TLFB) method-Form 90, which helps participants recall and mark days on which they used alcohol during the past 90 days.

12-Step fellowship engagement will be measured with the Multi-Dimensional Mutual-help Activity Scale (MDMAS), which measures seven dimensions of experience (meeting attendance, meeting participation, fellowship involvement, step work, mandated attendance, affiliation, and safety). Total score ranges from 32-160 with higher scores within indicating greater engagement.

Drinking consequences will be measured with the Short Inventory of Problems (SIP-2R). Score ranges from 0-45 with higher scores indicating a greater frequency of experiencing problems related to substance use.

Drug use will be measured with the aforementioned TLFB-Form 90

Psychological distress will be assessed with the 18-item Brief Symptom Inventory. Score ranges 0-72 and higher scores indicate greater levels of psychological distress.