Geographic disparities in EVT access and stroke mortality under universal health coverage in South Korea

Even in health systems with universal health coverage (UHC), disparities in access to time-sensitive stroke interventions may persist, leading to inequities in patient survival. I aimed to quantify regional disparities in access to endovascular thrombectomy (EVT) and 1-year mortality among patients with acute ischemic stroke (AIS) in South Korea and to assess associations with individual and regional healthcare factors. This retrospective cohort study analyzed the 2021 National Health Insurance Service claims data of 29,755 adults hospitalized with AIS across 250 administrative districts in South Korea. Districts were classified as having no EVT center, a low-volume EVT center (<24 annual cases), or a high-volume EVT center (≥24 annual cases per year). Multilevel logistic regression models were used to assess the association between individual- and regional-level factors with EVT receipt and 1-year mortality. Regional inequalities were further evaluated using Gini coefficients across the adjustment levels. Of the 29,755 patients, 22.5% resided in districts without EVT centers, 20.5% in low-volume districts, and 57.0% in high-volume districts. After adjusting for age, sex, comorbidities, and stroke severity, patients residing in high-volume districts were more likely to receive EVT (adjusted odds ratio [aOR], 1.27; 95% confidence interval [CI], 1.10–1.46) and had lower odds of 1-year mortality (aOR, 0.80; 95% CI, 0.73–0.89) than those residing in districts without EVT centers. Regional inequality in EVT access increased after adjustment for individual factors (Gini coefficient, 0.0948 to 0.1353), and mortality inequality also increased (0.0449 to 0.1184), indicating that crude comparisons underestimated the disparities. In a nationwide UHC system, regional disparities in EVT access and 1-year mortality were modest but persistent and associated with the availability of high-volume EVT centers. Expanding EVT capacity and strengthening prehospital–hospital networks in underserved regions may be associated with reduced inequities in stroke care and improve survival outcomes in patients with stroke.