This study examined the longitudinal association between the change in the step count of older adults and the neighborhood-built environment (BE) in Yokohama, Japan. We analyzed pedometer data in March 2016 and March 2019 that were acquired from 21,557 older adults aged 65-79 years at baseline, who lived in 758 neighborhoods in Yokohama City and participated in the Yokohama Walking Point Program (YWPP). Six BE variables were computed, for each of which neighborhoods were classified into quartiles. Using multilevel regression analysis, we examined the association between the BE variables, baseline step count, and change in step count. Higher population density, lower intersection density, and the second shortest quartile of the average distance to the nearest railway station were associated with a higher baseline step count. A lower intersection density and shorter average distance to the nearest railway station were associated with a smaller decline. The lowest quartile of population density was inversely associated with step-count decline. In conclusion, the neighborhood BEs were not only associated with their step count at baseline, but also widened the disparity of the step count over the three years. These findings would contribute to creating age-friendly cities where older adults can maintain and promote their health.
Keywords: compact city; multilevel analysis; neighborhood; physical activity; walkability.