Evaluating an Incentive-Based mHealth App for Physical Activity Promotion Using the Obesity-Related Behavioral Intervention Trial Model: Small Cohort Study
Background: Physical inactivity remains a public health concern, with 42% (around 1 in 2) of women and 34% (around 1 in 3) of men in the United Kingdom, for example, failing to meet moderate-to-vigorous physical activity guidelines. To promote physical activity (PA) at scale, smartphone-based mHealth (mobile health) software apps offer a promising solution. Objective: This study aims to evaluate the #feasibility of implementing an mHealth app offering very small (“micro”) financial incentives for PA in Leeds, United Kingdom. Methods: A 5-week single-arm proof-of-concept study was conducted with rolling recruitment among Caterpillar Health app users between September 12 and December 12, 2022 (Obesity-Related Behavioral Intervention Trial model, phase IIa). Users earned microincentives in the form of “points,” redeemable for consumer rewards (eg, movie tickets and gym passes), for meeting personalized daily step goals (US $0.13 per goal achieved; set using data from a 5-day baseline) and completing educational quizzes (US $0.33 per quiz). Descriptive statistics assessed #feasibility outcomes (ie, reach, recruitment, retention, engagement, and acceptability) and preliminary effectiveness. Paired-samples tests (
