A co-designed gamified mHealth platform for adolescents and young adults with intellectual and developmental...

Adolescents and young adults with intellectual and developmental disabilities (IDs) experience disproportionately low physical activity and high sedentary time yet remain insufficiently served by scalable and cognitively accessible health-enhancing physical activity (HEPA) programmes. This study reports proof-of-concept evidence for IDHEApp, a co-designed, gamified mobile health (mHealth) intervention integrated with a wearable activity tracker to promote physical activity in cognitively diverse users. We conducted an 8-week, convergent mixed-methods pilot randomised controlled trial across two European community IDs services (Rome, Italy; Rijeka, Croatia). Sixty adolescents and young adults were randomised (1:1) to an intervention arm (IDHEApp with Fitbit-enabled feedback and gamified step challenges) or a control arm (Fitbit monitoring plus usual routines). Quantitative outcomes were derived from wearable data (primary: daily step count; secondary: activity intensity and posture-related indicators) and analysed as exploratory behavioural signals using ANCOVA adjusted for baseline values. Qualitative data were obtained through two-phase focus groups (pre-implementation formative assessment and post-implementation technology exposure) with adolescents and young adults and caregivers and examined using reflexive thematic analysis. The intervention was technically feasible to deploy in real-world service settings at both sites. The strongest between-group signal was observed for daily steps (+2068 steps/day; p < 0.001), whereas activity-intensity and posture metrics demonstrated smaller and less consistent patterns. Thematic findings suggested that simple, non-competitive gamification (step goals, points, badges) was readily understood and perceived as motivating, supporting sustained engagement; however, technical barriers (Bluetooth pairing, synchronisation, device charging) increased reliance on caregiver support. Collectively, these findings indicate that IDHEApp is a promising mobile-wearable ecosystem to support HEPA in adolescents and young adults with IDs and justify further optimisation to enhance technical robustness, reduce caregiver burden, and evaluate effectiveness over longer follow-up periods.