A Just-in-Time Adaptive Intervention Based On Consumer-Grade Devices to Increase Physical Activity Among Individuals with Spinal Cord Injury

Research Category: Computer and Information Sciences

Motivation: Individuals with spinal cord injury (SCI) on wheelchairs are at considerable risk of mortality from cardiovascular diseases due to insufficient physical activity (PA)Regular PA and exercise interventions have shown to improve physical well-being.

Problem statement: Develop and deploy a mobile-based just-in-time-adaptive intervention (JITAI) to improve PA level among individuals with SCI.

Approach: A PA recognition algorithm was implemented in a JITAI system consisting of an Android smartphone application receiving data from a Bluetooth-enabled wheel-rotation monitor and a wrist-worn Android smartwatch. A three-month pilot study (n=20) involved 1) passive feedback starting at month-two: participants monitoring their daily Energy Expenditure (EE) and distance traveled in the app, and 2) active adaptive intervention starting at month-three: the app sending just-in-time tailored watch notifications to increase PA level.

Results: Six participants have completed the study. The average±SD age was 50.9±10.0 years. Four were male. PA levels for passive feedback (EE = 1900±374 kcal, low PA = 1191±230 min) and adaptive intervention (EE = 1926±379 kcal, low PA = 1175±229 min) trend higher than the baseline (EE = 1768±460 kcal, low PA = 1054±267 min). Moderate-to-vigorous PA remained similar for passive feedback (61±39 min), adaptive intervention (62±38 min), and baseline (64±36 min).

Conclusions: To our knowledge, this is the first study to evaluate a mobile technology-based JITAI to encourage PA by monitoring PA levels and providing both passive feedback and adaptive intervention to individuals with SCI. This study will lead to both qualitative and quantitative findings to inform the development of such systems.