Household financial management behavior and catastrophic health expenditure risk in rural China: the moderating role of health insurance coverage.

Introduction: Catastrophic health expenditure (CHE) represents a major cause of poverty among rural households in China. Although health insurance coverage in rural China exceeds 95%, CHE incidence remains high, and existing research has predominantly focused on external protection mechanisms such as health insurance, with insufficient attention to household financial management capacity. Methods: Drawing on data from 17,156 rural households in the 2019 China Household Finance Survey, this study constructed a financial management behavior index encompassing four dimensions: saving behavior, asset allocation, debt management, and insurance awareness. We employed logistic regression and instrumental variable methods to analyze the impact of financial management behavior on CHE and its interaction with health insurance. Results: Financial management behavior significantly reduces CHE risk, with saving behavior and insurance awareness demonstrating the strongest protective effects. Health insurance moderates this effect, weakening the protective role by approximately 70%, with stronger substitution among low-capacity households. The protective effect is greater among low-income households, western regions, and older-adult-headed households, exhibiting diminishing marginal utility. Different dimensions show complementary and substitutional relationships: savings' marginal effect is significantly higher in high-debt households, while debt management's effect is weaker in high-saving households. Discussion: These findings suggest that reducing CHE risk requires shifting from singular health insurance expansion toward differentiated "health insurance + financial capacity" strategies, implementing targeted interventions based on household financial capacity levels.