Background: This study aimed to examine trends in socioeconomic inequalities in sports group participation and daily walking time among older adults in Japan from 2016 to 2019, and to elucidate the association of municipal-level social capital in these trends.
Methods: Using data from the Japan Gerontological Evaluation Study across 2 waves (2016 and 2019), this repeated cross-sectional ecological study included 50 municipalities with 102,575 and 94,022 participants, respectively. We investigated inequalities in sports group participation, and daily walking time by income and education, using the slope index of inequality and relative index of inequality with municipal-level social capital variables, such as civic participation, reciprocity, social cohesion, and social network.
Results: From 2016 to 2019, all slope index of inequalities showed a decreasing trend (-4.2 to - 0.5), whereas relative index of inequalities maintained or decreased (-0.10 to 0.00). Increases in municipal-level social capital particularly civic participation and social networks with friends were associated with reduced inequalities in both sports group participation and walking time. For example, increased civic participation scores were associated with reduced relative index of inequalities, which assessed inequalities in sports group participation by income (B = -0.13, 95% CI, -0.24 to - 0.03) and in walking time by education (B = -0.06, 95% CI, -0.11 to - 0.01).
Conclusions: Enhancements in municipal social capital can reduce socioeconomic inequalities in sports group participation and daily walking among older adults, highlighting the importance of fostering civic participation, social networks, and cohesion in public health strategies aimed at reducing inequalities in sports and walking.