Just-in-Time Adaptive Interventions to Reduce Sedentary Behavior and Promote Physical Activity in Patients With Chronic Disease: Scoping Review.

BACKGROUND: Patients with chronic diseases often struggle to maintain sufficient physical activity (PA) and reduce sedentary behavior in daily life. Just-in-time adaptive interventions (JITAIs), delivered through mobile health technologies such as mobile apps, wearable devices, sensors, and ecological momentary assessment, offer timely and personalized support based on individuals' changing needs. However, the evidence base for their use in promoting PA and reducing sedentary behavior among patients with chronic diseases remains fragmented. OBJECTIVE: This review aimed to describe study characteristics and design features of JITAIs, summarize reported evaluation findings related to PA and sedentary behavior, and identify barriers and facilitators related to engagement and use of JITAIs. METHODS: A comprehensive literature search was conducted in PubMed, Embase, Web of Science, CINAHL, and Scopus from database inception to June 2025. Two researchers independently screened the records, selected eligible studies, and performed data charting to ensure rigor and consistency. RESULTS: A total of 14 studies were included in this review. Of these, 6 primarily targeted PA, 1 focused solely on sedentary behavior, and 5 addressed both PA and sedentary behavior. Of the remaining, 6 studies provided preliminary evidence supporting the positive effects of JITAIs in promoting PA among individuals with chronic diseases, while 3 studies suggested positive effects on reducing sedentary behavior. Barriers and facilitators influencing the use of JITAIs in this population were identified. Barriers included technological usability and literacy, burden and intrusiveness of the intervention, perceived value and acceptability, external and contextual barriers, and privacy and data security concerns. Facilitators included enhanced motivation and behavioral engagement, increased awareness and self-monitoring, usability and integration into daily life, timely and personalized support, and support from health care professionals and the care environment. CONCLUSIONS: This scoping review identified preliminary evidence suggesting that JITAIs may help reduce sedentary behavior and promote PA among patients with chronic diseases. However, more large-scale, high-quality randomized controlled trial studies are needed to strengthen evidence and generalizability.