Active travel effects of mHealth app that exchanges daily walking steps for digital train tickets: Quasi-experimental study using HealthSmart-Senboku

This study investigated the active travel effects of an mHealth app that exchanges daily walking steps for digital train tickets via the mHealth app called HealthSmart-Senboku. The mHealth app is a local smartphone app for residents and visitors to Senboku New-Town, Japan. The mHealth app has two unique incentives. The first point is the incentives of exchanging daily walking steps for shopping coupons in selected local stores in Senboku New-Town. The second point is an incentive to exchange daily walking steps for digital train tickets on the Senboku Line. The study design was a quasi-experimental study. The analysis period was approximately 13 months (8 months baseline and 5 months exposure periods). Our analysis set the outcome as daily walking steps, which were automatically recorded by the mHealth app. The treatment group is the train ticket user group. The covariate is the shopping coupon user group. The potential confounders are gender and age. This study adopted a difference-in-differences regression analysis. This study revealed that the mHealth app's incentives to exchange for train tickets increased users' daily walking steps by 626.243 [0.266, 1252.220] steps/day for 5 months at a 5 % significance level. The sensitivity analyses rigorously verified the robustness of the findings. The active travel effect of HealthSmart-Senboku was greater than that of other mHealth apps. In addition, the daily walking steps of the shopping coupon user group were 715.211 [277.418, 1153.004] steps/day greater than those of the shopping coupon non-user group. This study concludes that HealthSmart-Senboku's ticket exchange incentives promote active travel among users. The reason might be related to the incentive design of mHealth apps based on active travel on public transportation. Our findings indicate the effectiveness of mHealth apps in providing incentives to encourage the use of public transportation in New-Towns. • Examine the active travel effects of the mHealth app called Health-Smart-Senboku. • Health-Smart-Senboku app can exchange daily walking steps for digital train tickets. • Quasi-experimental study adopted a difference-in-differences regression analysis. • The app increased by 626.243 [0.266, 1252.220] steps/day significantly. • The mHealth app's ticket exchange incentives promoted active travel among users.