Association between catastrophic health expenditure and mental health among elderly in China: the potential role of income and social activity.

Background: Little is known about the association between catastrophic health expenditure (CHE) and mental health in elderly population and its potential moderators. This study examined the relationship between CHE and depressive symptoms in Chinese older persons and its difference between groups of different income level and social activity engagement.

Methods: We employed data from the 4 waves (2011, 2013, 2015, and 2018, N = 15,406) of the China Health and Retirement Longitudinal Study (CHARLS). A linear mixed model was used to examine the association between depressive symptoms and CHE, and interaction terms were involved in the model to examine the moderating role of social activity and income levels.

Results: Significant correlations have been shown between CHE and depressive symptoms(coefficient = 0.363, P < 0.05), such association was more pronounced in socially inactive (P = 0.034, Difference = 0.37, interaction terms (social activity*CHE: -1.189) or low-income seniors (P < 0.001, Difference = 0.77, interaction terms (medium income*CHE: -0.594, P < 0.05, high income*CHE: -0.667, P < 0.01), and especially in socially inactive and low-income seniors (P < 0.001, Difference = 0.93, interaction terms (high income*CHE*social acitivity: 1.132, P < 0.05). Even after increasing the threshold of CHE to 20% and 25%, similar pattern was observed.

Conclusions: This study suggest a positive association between CHE event and depressive symptoms, as well as the protective effect of advantaged financial status and engagement of social activity. Our finding provide empirical evidence to call for urgent action for government and public health authorities, to address the high medical expenditure, psychological stress among elderly, especially for low-income households or elderly living alone.