JMIR Publications

ABSTRACT

Background:

Just-in-time-adaptive-interventions (JITAIs) provide real-time ‘in the moment’ behaviour change support to people when they need it most. JITAIs could be a viable way to provide personalised physical activity support to older adults in the community. However, it is unclear how feasible it is to remotely deliver a physical activity intervention via a smartphone to older adults, or how acceptable older adults would find a JITAI targeting physical activity in everyday life.

Objective:

(1) to describe the development of “JITABug”, a personalised smartphone and activity tracker delivered JITAI designed to support older adults to increase or maintain their physical activity level; (2) to explore the acceptability of JITABug in a free-living setting, and (3) to assess the feasibility of conducting an effectiveness trial of the JITABug intervention.

Methods:

The intervention development process was underpinned by the Behaviour Change Wheel. The intervention consisted of a wearable activity tracker (Fitbit) and a companion smartphone app (JITABug) which delivered goal setting, planning, reminders, and just-in-time adaptive messages to encourage achievement of personalised physical activity goals. Message delivery was tailored based on time of day, real-time physical activity tracker data, and weather conditions. We tested the feasibility of remotely delivering the JITAI with older adults in a 6-week trial using a mixed-methods approach. Data collection involved assessment of physical activity by accelerometery and activity tracker, self-reported mood and mental wellbeing via ecological momentary assessment, and contextual information on physical activity via voice memos. Feasibility and acceptability outcomes included: (1) recruitment capability and adherence to the intervention; (2) intervention delivery ‘in the wild’; (3) appropriateness of data collection methodology; (4) adverse events and; (5) participant satisfaction.

Results:

Of 46 recruited older adults (aged 56-72 years old), 65% completed the intervention. The intervention was successfully delivered as intended; 27 participants completed the intervention independently, 94% of physical activity messages were successfully delivered, and 99% of Fitbit and 100% of weather data calls were successful. Wrist-worn accelerometer data were obtained from 96% at baseline and 96% at follow up. On average, participants recorded 8/16 (50%) voice memos, 3/8 (38%) mood assessments, and 2/4 (50%) wellbeing assessments via the app. Overall acceptability of the intervention was very good (77% satisfaction). Participant feedback suggested that more diverse and tailored physical activity messages, app usage reminders, technical refinements regarding real-time data syncing, and an improved user interface could improve the intervention and make it more appealing.

Conclusions:

This study suggests that a smartphone delivered JITAI utilizing a wearable activity tracker is an acceptable way to support physical activity in older adults in the community. Overall, the intervention is feasible, however based on user feedback, the JITABug app requires further technical refinements that may enhance usage, engagement, and user satisfaction before moving to effectiveness trials. Clinical Trial: Non-Applicable