The mediating effect of built environment on the relationship between socioeconomic status and mental health: findings from the 2019 Shanghai community survey

Abstract Objective: Based on the theory of spatial production, the built environment is considered a mediating mechanism for health inequality. This study tested the hypothesis that communities, where populations with a higher socioeconomic status live, have a higher-quality built environment, which, in turn, promotes their mental health. Methods: Based on data from the 2019 Shanghai Community Survey (n=3233), the general linear regression model (OLS) and the classical three-step method developed by Baron and Kenny (1986) were used to test the mediation effects; subsequently, a structural equation model (bootstrap) was used to examine average direct effects (ADE) and average causal mediation effects (ACME). Results: There were fewer types of aversive facilities, more green spaces or sports fields conducive to leisure and exercise, and better environmental hygiene in communities with higher-income populations, all of which improved their mental health. The total effect of income on mental health was 0.145 ( P <0.001), of which the ACME effect through the built environment was 0.013 ( P <0.05), accounting for approximately 8.97%. Among the three dimensions of the built environment, the sanitation environment had a greater effect, accounting for 55.07% of the total mediation effect. Surrounding facilities accounted for 34.73%, while community green and sports spaces accounted for approximately 10.19%. Conclusions: The built environment quality of communities where low-income groups reside is worse, resulting in lower levels of their mental health. In the spatial planning of built environments, the socioeconomic characteristics of different residential groups should be considered, and the environmental quality of low-income communities should be improved using targeted measures.