[The association between public transportation electric-powered cart stoppage and the risk of incident functional disability in older people: A longitudinal study comparing three waves of data (pre-operation, post-operation, and post-stoppage)].

Objective Green-slow mobility (electric-powered carts), with travel speeds below 20 km/h on public roads, is expected to promote outings and social participation, potentially reducing the risk of functional disabilities. When electric-powered cart operations stop in a community, outings and social connections may decrease, thereby increasing the risk of functional disability. This study investigated whether the risk of functional disability increased among users after electric-powered cart operation ended.Methods This longitudinal study employed a natural experimental design and analyzed three waves of data: before electric-powered carts were introduced, during operation/immediately after operation stopped, and sometime later (post-stoppage). For each wave, data were gathered through a self-administered survey. After operation stopped, secondary analyses were conducted. Electric-powered carts remained out of service for four months following the demonstration project's conclusion. Participants included 78 adults over age 65 residing in Nitto, Taishi, and Kawachinagano. They completed all three surveys and reported using electric-powered carts at least once monthly during operation. The primary outcome variable was the risk assessment scale, which predicts the likelihood of requiring long-term care within three years (range: 0-48, with higher scores indicating a greater risk). The primary explanatory variables were survey waves (preoperative, during the operation/immediately after operations stopped, and post-stoppage). Covariates included baseline characteristics, such as sex, education, marital status, employment, economic hardship, and living alone. A linear mixed-effects model was used to analyze the data, reporting coefficients (B), 95% confidence intervals (CI), and P values. Additional analyses stratified the participants by cart usage frequency (at least once weekly vs. 1-3 times monthly).Result Among people who used carts at least once weekly (n = 31, 39.7%), the mean risk scores were the lowest during operation/immediately after operation stopped (20.0) and the highest post-stoppage (21.8). The coefficient of the association between survey timing and risk scores was 0.01 (-0.78-0.81, P = 0.975) during operation/immediately after operation stopped, and 0.49 (-0.31-1.28, P = 0.231) after post-stoppage. For people using carts at least once/week, the association was 0.71 (-0.75-2.17, P = 0.341) pre- and 1.77 (0.31-3.24, P = 0.017) post-stoppage. No significant associations were found for those using carts 1-3 times monthly.Conclusion Stopping electric-powered cart operations may increase the risk of long-term care, particularly for [at least] once weekly users. Sustained cart usage is vital for healthy aging among older adults.