Abstract
BACKGROUND AND OBJECTIVES: Limited longitudinal study exists on the combined effects of environmental factors and life-course socioeconomic status (SES) on multimorbidity in China. This study aims to explore the cumulative impact of age-friendly neighborhoods on multimorbidity over time, focusing on SES moderation. RESEARCH DESIGN AND METHODS: Analyzing data from 10, 125 participants in the China Health and Retirement Longitudinal Survey (2011-2020), this study assessed multimorbidity through self-reported chronic diseases and evaluated neighborhood environments using 8 domains from the Age-Friendly Cities and Communities framework. Childhood and adulthood SES were measured using latent class analysis. Latent growth curve models examined the effects of neighborhood environment, life-course SES, and their interactions on multimorbidity. RESULTS: The study found a statistically significant increase in multimorbidity over time, with an intercept of 0.514 and a slope of 0.085. Notably, government support showed an independent association with the baseline number of chronic diseases (β = -0.078, p < .1). The interaction between government support and childhood SES was also significant (β = -0.183, p < .05), suggesting that unfavorable childhood SES could reduce the protective effects of government support. Additionally, adulthood SES interacted with factors such as information infrastructure (β = -0.068, p < .001) and neighborly support (β = -0.092, p < .1), and transportation interacted with childhood SES (β = -0.028, p < .05), all negatively affecting the rate of change in multimorbidity. These findings suggest that individuals with higher SES derive greater benefits from these age-friendly neighborhood environment domains compared to their lower SES counterparts. DISCUSSION AND IMPLICATIONS: Age-friendly neighborhoods with strong government support, neighborly support, and developed infrastructure slow multimorbidity progression. However, these benefits are influenced by life-course SES. Policymakers should consider disadvantaged populations' access to environmental resources and address potential neighborhood socioeconomic health inequalities.