A Smartphone-Based Shopping Mall Walking Program and Daily Walking Steps.

Importance: Because shopping malls are considered safe places for walking, several mall walking programs have been developed. Research on the association between the use of walking programs and the number of daily steps taken is limited. Objective: To evaluate the association between use of a smartphone-based shopping mall walking program and daily steps taken after the COVID-19 pandemic. Design, Setting, and Participants: This cohort study evaluated a nationwide longitudinal data set of 217 344 registered smartphone app users at least 18 years of age residing in Japan. Daily step counts were collected from January 1 to December 31, 2021. Exposures: The mall walking program Mall Challenge integrated a global positioning system with a smartphone app's incentive system to reward achieving a goal of 1000 daily steps with lottery-based coupons to win from 0 to 500 shopping points (1 point equaled 1 yen or approximately US $0.01). Main Outcomes and Measures: Daily step records were collected from the smartphone app's walking program and adjusted for gender and age. Multilevel analyses using mixed-effect linear regression models were used to estimate the coefficients for the association between daily participation in the walking program and daily step counts. Cross-level interaction terms of age and gender by walking program participation were included in one model. Results: Among the 217 344 registered mall app users (23 638 110 daily step records; 154 616 [71.1%] women; 18 014 [8.3%] participants 65 years or older, and 199 330 [91.7%] adults younger than 65 years), the mean (SD) daily steps were 7415 (4686) on walking program participation days and 5281 (4339) on days without participation in the program. Walking program participation days were associated with 1219 additional daily steps (95% CI, 1205-1232) compared with nonparticipation days after adjusting for gender and age. By geographic region, participation in the walking program was associated with 1130 (95% CI, 1113-1146) more steps in rural malls, 1403 (95% CI, 1379-1428) more steps in suburban malls, and 1433 (95% CI, 1408-1457) more steps in urban malls than nonparticipation. Moreover, participation in the walking program was associated with 1422 (95% CI, 1405-1439) more steps in large malls and 1059 (95% CI, 1041-1077) more steps in small malls compared with nonparticipation. Regarding cross-level interactions, women were associated with walking 728 (95% CI, 698-758) more steps than men, and older adults were associated with walking 228 (95% CI, 183-273) more steps than younger adults on walking program participation days. Conclusions and Relevance: This cohort study found that the use of a smartphone-based mall walking program combined with physical shopping mall facilities and lottery-based digital incentive coupons may motivate people to increase their daily number of walking steps.