Sense of control as a mediator of the association between social capital and health inequality in China

Social capital was shown to be associated with health. However, less is known about the pathways of the as-sociation and whether the mediating effect of the pathways varies across different income groups. Using adults (>= 18 years) data from the 2010 Chinese General Social Survey (N = 3265), we examined the mediating effect of sense of control between social capital and health and whether income groups moderated the mediating effect in China. Health and sense of control were factor scores. Social capital measurements included frequency of so-cializing, civic participation, trust, and reciprocity. We categorized equivalized household income into quintiles (Q1 (lowest income) to Q5 (highest income)). Multivariable linear regression models showed that frequency of socializing (8: 0.07; 95% CI: 0.04, 0.11), trust (8: 0.06; 95% CI: 0.02, 0.09), and reciprocity (8: 0.07; 95% CI: 0.03, 0.11) were positively associated with health. Moderated mediation analysis further showed that sense of control mediated the association between frequency of socializing and health in all income groups, with the mediating effect decreasing when income increased (8 (95% CI) from Q1 to Q5: 0.026 (0.015, 0.040); 0.022 (0.012, 0.036); 0.018 (0.009, 0.030); 0.013 (0.005, 0.024); 0.008 (0.000, 0.018)). Moderated mediation analysis also showed the same patterns for the mediating effect of sense of control on the association between trust and health and reciprocity and health. Our study suggested that employing social capital to promote sense of control could not only be beneficial for people's health but also be helpful to narrow the health gap on the income gradient.