Abstract
IMPORTANCE: Stroke is a major cause of morbidity and mortality. Timely administration of intravenous thrombolysis (IVT) is essential for improving outcomes for patients with acute ischemic stroke. Significant disparities exist in IVT administration based on socioeconomic and racial and ethnic backgrounds. Understanding how hospital-level segregation is associated with stroke treatment outcomes is crucial for addressing these disparities. OBJECTIVE: To investigate the association between hospital segregation, using the Index of Concentration at the Extremes (ICE), and IVT administration rates among patients with stroke. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study used US hospital data from the 2016-2020 National Inpatient Sample database. Using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Clinical Modification codes, patients admitted to hospitals with acute ischemic stroke were included. Statistical analysis was performed from March through July 2024. EXPOSURE: Hospital segregation measured by the ICE, quantifying socioeconomic and racial and ethnic extremes within hospitals. ICE values range from -1 (predominantly Black and socioeconomically disadvantaged) to 1 (predominantly White and socioeconomically advantaged). Hospitals were categorized into ICE quintiles, with the first quintile representing the most disadvantaged hospitals, the third quintile representing a balanced patient mix, and the fifth quintile representing the most privileged hospitals. MAIN OUTCOMES AND MEASURES: The primary outcome was IVT administration rates. Secondary outcomes included racial and ethnic disparities in IVT administration across ICE quintiles. RESULTS: Among 2 494 945 patients with stroke, the mean (SD) age was 70.1 (14.0) years, 50.2% were male, 0.5% were American Indian, 3.1% were Asian or Pacific Islander, 17.4% were Black, 8.2% were Hispanic, 68.2% were White, and 2.6% were other race or ethnicity. Of these patients, 65.4% were treated at hospitals in the third ICE quintile, while 1.2% of patients were treated at hospitals in the first ICE quintile. Patients at hospitals in the fourth and fifth ICE quintiles were significantly more likely to receive IVT (fourth quintile: adjusted odds ratio [AOR], 1.32 [95% CI, 1.26-1.38]; fifth quintile: AOR, 1.27 [95% CI, 1.21-1.34]) compared with those in the first quintile. Racial and ethnic disparities in IVT administration were most pronounced in the first ICE quintile, where Black patients were 32% less likely than White patients to receive IVT (AOR, 0.68 [95% CI, 0.58-0.79]). This disparity decreased but persisted in higher quintiles. CONCLUSIONS AND RELEVANCE: In this study of hospital segregation and IVT administration rates, segregation was associated with lower likelihood of IVT administration for patients at hospitals serving predominantly Black and socioeconomically disadvantaged communities. Socioeconomic improvements were associated with reduced, but not eliminated, racial and ethnic disparities in stroke treatment. Addressing structural racism and segregation is crucial for equitable access to stroke care.