Catastrophic health expenditure and its inequality in rural China: based on longitudinal data from 2013 to 2018

BACKGROUND: Catastrophic health expenditure (CHE) is an important indicator of measuring health inequality. Previous studies mainly focused on specific vulnerable populations rather than a wider range of vulnerable areas through panel data. Rural China is often associated with an underdeveloped economy and insufficient health resources. This study aims to update the information on the extent of and trends in the incidence and inequality of CHE among the households of rural China through longitudinal survey data. METHODS: Data were obtained from three waves of the China Health and Retirement Longitudinal Study (CHARLS): 2013, 2015, and 2018. In total, 2,575 households were included in the analysis. CHE was defined as household health expenditures exceeding 40% of non-food expenditures. Inequality in CHE was measured using the concentration curve and concentration index. The contribution to CHE inequality was decomposed using the concentration index decomposition method. RESULTS: The incidence of CHE was 0.2341 (95% CI: 0.22, 0.25) in 2013, 0.2136 (95% CI: 0.20, 0.23) in 2015, and 0.2897 (95% CI: 0.27, 0.31) in 2018 in rural China. The concentration curve lay above the equality line, and the concentration index was negative: −0.1528 (95% CI: −0.1941, −0.1115) in 2013, −0.1010 (95% CI: −0.1442, −0. 0577) in 2015, and −0.0819 (95% CI: −0.1170, −0.0467) in 2018. Economic status, age, and chronic diseases were the main contributors to inequality in CHE. CONCLUSIONS: The incidence of CHE in rural China displayed an upward trend from 2013 to 2018, although it was not continuous. Furthermore, a strong pro-low-economic inequality in CHE existed in rural China. Mainly economic status, age, and chronic diseases contributed to this pro-low-economic inequality. Health policies to allocate resources and services are needed to satisfy the needs of rural households and provide more accessible and affordable health services. More concern needs to be directed toward households with chronic diseases and older persons to reduce the incidence of CHE and promote health equality. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-023-16692-7.