吉田 紘明

Japan's population has been aging steadily, evidenced by it spending JPY 11 trillion (USD 110 billion) on annual long-term care (LTC) costs in 2021. In this context, understanding the factors influencing LTC costs has become increasingly vital. Although studies have reported positive relationships between neighborhood environment and health outcomes, the connection between LTC costs and neighborhood environment remains unclear. To address this gap in the literature, this cohort study, conducted from 2010 to 2019 across seven Japanese municipalities and involving 34,982 older people, examined the relationship between eight neighborhood environment elements and the mean monthly cumulate costs (MMCC) of LTC. The results showed that older people who reported the presence of fresh food stores nearby and dangerous places for walking alone at night in the neighborhood had lower MMCC, by JPY 1,367.6 and 1,383.3 per month, respectively, than respondents who did not report the presence of these neighborhood elements. Meanwhile, older people whose neighborhoods had easily accessible facilities had higher MMCC of JPY 739.4. This study's key findings reveal significant relationships between neighborhood environment elements and LTC costs and can be used to support developments in urban design to support healthy aging and reduced LTC costs.

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.