Can family health alleviate income-related health disparity in China? A population-based study

BACKGROUND: Family health is an important variable that links internal and external resources at the family level, exerting significant effects on individual health. However, there remains a lack of empirical evidence regarding its potential to mitigate health disparities. Therefore, the present study aimed to explore the effect of family health on income-related health disparity in China and analyze the heterogeneous effects of different dimensions of family health across different sub-populations. METHODS: Using nationally representative data from the 2023-2024 Psychology and Behavior Investigation of Chinese Residents [n = 49,885], we employed health-related quality of life (HRQoL) as a proxy variable for individual health and applied the recentered influence function-index-ordinary least squares model to explore the contributions of family health and its four dimensions to the disparity in HRQoL. RESULTS: Our findings showed that family health had a significantly negative association with the concentration index of health utility index (UI; β = -0.0002, P < 0.05) and EuroQol Visual Analogue Scale (EQ-VAS; β = -0.0006, P < 0.01). Family social or emotional support was negatively associated with EQ-VAS disparity, and family external social support significantly contributed to lower UI disparity. However, family health resources were positively associated with the disparity in UI and EQ-VAS. Heterogeneity analysis revealed more pronounced effects of family health in mitigating health disparity among females, young populations, and urban residents. CONCLUSIONS: This study emphasizes the importance of alleviating health disparities through family health improvement. In addition, the study findings demonstrate the necessity of reshaping resource allocation at the family level-balancing external supply and internal equity of families among different subgroups-and accelerating the distribution of high-quality medical resources to economically disadvantaged areas.