Designing mHealth Apps for Substance Use Recovery: A Mixed-Methods Study with Real World Co-Design and Deployment (Preprint)

BACKGROUND Mobile health applications (mHealth apps) have shown promise to support recovery from substance use disorders. However, evidence on engagement and efficacy is still inconclusive. OBJECTIVE This work analyzed the real world usage of new mHealth app features among people aiming to address problematic substance use to investigate how to optimize app engagement. METHODS An mHealth app was co-designed, deployed, and evaluated. Initial co-design interviews with 14 individuals in recovery led to new features integrated into an existing mHealth app, which was then deployed for a six-week trial with 53 participants. Follow-up interviews with 12 app-users foregrounded usage experiences and design considerations. RESULTS Three new features were developed from co-design interviews: a goal-setting feature, a craving tracker, and a meetings log. Usage metrics revealed mixed engagement: 24/53 users actively engaged with the app throughout the trial, and 30-day retention rates exceeded typical industry benchmarks, at 45.83% among active participants. According to qualitative analysis, participants prefer when apps adopt a holistic approach to recovery, with functionality extending beyond substance use domains. They preferred mHealth apps to bridge functionality by acting as private digital journals while also providing a sense of community and connection to broader recovery ecosystems. Allowing users to determine their own personalized recovery pathways in mHealth apps can lead to a twofold effect on engagement, with some users benefiting from increased autonomy and others becoming overwhelmed by a lack of direction. CONCLUSIONS It is valuable to incorporate iterative co-design methodologies into digital health and recovery app research to help optimize engagement. Furthermore, recovery apps can benefit from flexible designs with customizable degrees of user autonomy. Future designers can use personalized mHealth designs to strike a balance between system control and user control over digital recovery pathways to better cater to individual user preferences.