Association of Medicare-Medicaid Dual Eligibility and Race and Ethnicity With Ischemic Stroke Severity

IMPORTANCE: Black and Hispanic US residents are disproportionately affected by stroke incidence, and patients with dual eligibility for Medicare and Medicaid may be predisposed to more severe strokes. Little is known about differences in stroke severity for individuals with dual eligibility, Black individuals, and Hispanic individuals, but understanding hospital admission stroke severity is the first important step for focusing strategies to reduce disparities in stroke care and outcomes. OBJECTIVE: To examine whether dual eligibility and race and ethnicity are associated with stroke severity in Medicare beneficiaries admitted to acute hospitals with ischemic stroke. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cross-sectional study was conducted using Medicare claims data for patients with ischemic stroke admitted to acute hospitals in the United States from October 1, 2016, to November 30, 2017. Data were analyzed from July 2021 and January 2022. EXPOSURES: Dual enrollment for Medicare and Medicaid; race and ethnicity categorized as White, Black, Hispanic, and other. MAIN OUTCOMES AND MEASURES: Claim-based National Institutes of Health Stroke Scale (NIHSS) categorized into minor (0-7), moderate (8-13), moderate to severe (14-21), and severe (22-42) stroke. RESULTS: Our sample included 45 459 Medicare fee-for-service patients aged 66 and older (mean [SD] age, 80.2 [8.4]; 25 303 [55.7%] female; 7738 [17.0%] dual eligible; 4107 [9.0%] Black; 1719 [3.8%] Hispanic; 37 715 [83.0%] White). In the fully adjusted models, compared with White patients, Black patients (odds ratio [OR], 1.21; 95% CI, 1.06-1.39) and Hispanic patients (OR, 1.54; 95% CI, 1.29-1.85) were more likely to have a severe stroke. Using White patients without dual eligibility as a reference group, White patients with dual eligibility were more likely to have a severe stroke (OR, 1.75; 95% CI, 1.56-1.95). Similarly, Black patients with dual eligibility (OR, 2.15; 95% CI, 1.78-2.60) and Hispanic patients with dual eligibility (OR, 2.50; 95% CI, 1.98-3.16) were more likely to have a severe stroke. CONCLUSIONS AND RELEVANCE: In this cross-sectional study, Medicare fee-for-service patients with ischemic stroke admitted to acute hospitals who were Black or Hispanic had a higher likelihood of worse stroke severity. Additionally, dual eligibility status had a compounding association with stroke severity regardless of race and ethnicity. An urgent effort is needed to decrease disparities in access to preventive and poststroke care for dual eligible and minority patients.