Prevalence and Intensity of Catastrophic Health Expenditure Among Residents in a Multiethnic Province in China: Cross-Sectional Study

Background Hainan is a pilot free trade port in China and a multiethnic province. Catastrophic health expenditure (CHE) reflects health care inequity, particularly affecting vulnerable groups in rapidly developing multiethnic regions. Objective This study aims to analyze CHE prevalence and intensity and their influencing factors among residents in a Chinese multiethnic province. Methods Data from the 2023 Hainan Province Health Services Survey, conducted among 14,532 individuals aged 18 years or older, were used in a multistage stratified cluster sampling. CHE was defined as out-of-pocket health care payments exceeding 40% of the household’s capacity to pay. The chi-square test and a logistic regression were used to identify influencing factors for CHE. Nonparametric tests and quantile regression were used to evaluate the influencing factors for CHE intensity. Results The prevalence of CHE in Hainan province was 8.37%, with a median intensity of 17.67% (IQR 8.31%-29.77%). Residents were more likely to experience CHE if they were older than 60 years (odds ratio OR 1.928, 95% CI 1.602-2.320; P<.001), unmarried (OR 1.241, 95% CI 1.075-1.433; P=.003), or had chronic illnesses (OR 2.214, 95% CI 1.930-2.540; P<.001). Ethnic minority groups (OR 0.774, 95% CI 0.679-0.883; P<.001) as well as middle-income (OR 0.722, 95% CI 0.600-0.869; P=.001), high-middle-income (OR 0.739; 95% CI 0.609-0.898; P=.002), and high-income (OR 0.591, 95% CI 0.474-0.738; P<.001) groups were less likely to experience CHE. At lower CHE intensity (20th percentile), individuals older than 60 years (β=1.935; P=.03) and middle-income (β=1.737; P=.04) and rural (β=2.202; P=.005) residents showed positive associations. At the 50th percentile, low-middle-income (β=–5.052; P=.005), high-middle-income (β=–4.203; P=.03), and high-income (β=–6.534; P=.004) groups showed negative associations. At the 80th percentile, high-middle-income (β=–7.143; P=.03) and rural (β=–6.241; P=.005) groups showed stronger financial protection. Conclusions Addressing CHE risks remains a critical challenge in Hainan province, highlighting structural inequities rooted in socioeconomic disparities and health vulnerabilities. Therefore, policy should prioritize primary prevention in the lowest-income populations while implementing enhanced insurance coverage for rural populations facing extreme costs to alleviate the most severe financial burdens.