Determinants of catastrophic health expenditure: Evidence from a patient survey at public hospitals in the Northern midlands and mountainous areas, Vietnam

Background Catastrophic health expenditure (CHE) represents a critical barrier to universal health coverage, often pushing households into poverty and deepening financial hardship for vulnerable populations. This study examines determinants of CHE among patients attending public hospitals in the Northern Midlands and Mountainous areas of Vietnam. Design and methods A cross-sectional study was conducted from July to December 2021 among 706 patients recruited via multi-stage stratified sampling from 10 public hospitals across five provinces. Data were collected through structured face-to-face interviews. CHE was defined as out-of-pocket health expenditure exceeding 40% of non-food expenditure. Binary logistic regression was employed to identify determinants of CHE. Findings Among 706 participants, 147 (20.82%) experienced CHE. CHE cases were concentrated in the poorest income quintile (34.69%) and lowest in the richest (5.44%). Patients experiencing CHE were also disproportionately represented among those diagnosed with cancer (28.57% vs. 5.19% in the non-CHE group), reported higher rates of self-treatment (46.94%), and had more frequent inpatient visits. Key factors positively associated with CHE included cancer (OR = 6.438), self-treatment (OR = 2.798), treatment at provincial hospitals (OR = 2.099), inpatient visit frequency (OR = 1.160), and greater distance to health facilities. Factors negatively associated with CHE included health insurance coverage (OR = 0.579), Kinh ethnicity (OR = 0.319), and higher satisfaction with the availability (OR = 0.594) and quality of medicines (OR = 0.565). Conclusions The findings highlight the need to strengthen health insurance coverage for vulnerable households, improve district-level services, and reinforce primary healthcare, with relevance for other resource-constrained settings.