Associations Between Measures of Structural Racism and Acute Ischemic Stroke Outcomes in the United States

BACKGROUND: Structural inequity, including structural racism, is linked to stroke measures. Prior work showed that ecosocial models quantifying constituent domains of structural racism are associated with acute ischemic stroke incidence. It remains unclear if such models can further account for the not-yet-fully explained racial disparities in stroke outcomes. METHODS: We performed a national, population-based analysis of 71 078 619 Medicare beneficiaries aged ≥65 years enrolled in Medicare from January 1, 2016 to December 31, 2019 of whom 844 406 had a primary diagnosis of acute ischemic stroke. We estimated the odds ratio and 95% CIs of 3 outcomes (inpatient mortality, 30-day mortality, and discharge home) using multilevel logistic models, with data clustered at the county level. County-level data from the US Census Bureau and Home Mortgage Disclosure Act were used to calculate 8 measures of structural racism. These were tested separately and as a summed, normally distributed composite structural racism score for associations with the outcomes, adjusting for sex, age, urban versus other location, and Black versus White race. RESULTS: For each SD increase in the composite structural racism score, there was a 16% increase in poststroke inpatient mortality for the total population (odds ratio, 1.160 [95% CI, 1.10–1.215]) without a significant interaction with race ( P =0.624). Both 30-day all-cause mortality ( P =0.035) and odds of discharge home ( P =0.023) significantly interacted with race. For each SD increase in the composite score, Black individuals had a 4.5% increased odds of 30-day mortality and a 5.8% decreased odds of being discharged home, whereas White patients had a 6.5% increase in 30-day mortality and a 3.5% decrease in odds of discharge home. CONCLUSIONS: Increasing levels of structural racism, as calculated using validated quantitative measures of an ecosocial model of structural racism, are correlated with increasing poststroke mortality and decreased odds of discharge home, regardless of race.