JMIR Publications

ABSTRACT

Background:

Digital interventions have been successfully used to address addictive behaviors, such as substance use, in adolescents and young adults. However, maintaining engagement remains a challenge for digital substance use interventions. There is limited evidence on the determinants of engagement with multiple behavioral interventions among vocational students.

Objective:

This paper aims to describe engagement of vocational school students with the app-based addiction prevention program "ready4life" and to analyze student characteristics as potential determinants of engagement.

Methods:

A two-arm cluster-randomized trial evaluated "ready4life" among German vocational students aged 16+. After downloading the app during class, students completed an anonymous screening and received an individual risks and competencies feedback. Intervention participants (n=1286) received four months individual app-based coaching, with weekly chat contacts with a virtual coach. They were asked to choose two out of six modules: alcohol, tobacco, cannabis, social media/gaming, stress and social competencies that were delivered sequentially in a random order. In addition to the weekly chats, users could self-initiate chat dialogues at any time. Chats included media (videos, images, links), quizzes and contests. Control participants (n=1282) received a link to health behavior information and could access coaching after 12 months.

Results:

Engagement was low among intervention participants who received their assigned intervention (n=1266; female 44.9%; mean age 19.53, SD 3.57). On average, participants started 4.8 (SD 5.1) and completed 4.3 (SD 5.2) out of 16 weekly in-app chats. Most students (903/1266, 71.3%) completed no self-initiated chats, and 50.2% stopped using the app before week 3. Negative binomial multilevel regression models showed that a significantly higher number of completed weekly dialogues was observed for females (P<.001; IRR 1.55, 95% CI 1.33-1.80), individuals with lower self-efficacy (P=.037; IRR 0.96, 95% CI 0.93-0.998), lower social competencies (P<.001; IRR 0.97, 95% CI 0.95-0.98), and individuals engaging in less addictive behaviors (P<.001; IRR 0.87, 95% CI 0.82-0.93). With respect to specific educational tracks, professionals, technicians, associate professionals and vocational grammar school students had the highest number of completed weekly dialogues. Determinants of completed self-initiated chats and usage time largely aligned with the findings for weekly dialogues. In addition, those with higher perceived stress completed significantly more self-initiated chats (P<.001; IRR 1.19, 95% CI 1.08-1.31). Age and year of education were not significantly associated with any of the engagement parameters.

Conclusions:

Our study supports the existing evidence that keeping adolescents and young adults engaged is still a major challenge in digital interventions. An important finding was that students with higher needs for support in terms of self-efficacy, social competence, and perceived stress showed higher engagement. In terms of health equity, additional efforts should be made to increase program engagement among males, those with lower levels of education, and those with higher levels of addictive behaviors. Clinical Trial: German Clinical Trials Register (DRKS): DRKS00022328