Racial Disparities in Longitudinal Functional Outcome After Ischemic Stroke

BACKGROUND: The burden of stroke is unequally distributed in the United States, with Black individuals experiencing more incident stroke. It remains unclear whether Black individuals also experience worse stroke recovery. We sought to study disparities in longitudinal functional outcome after acute ischemic stroke in a population-based study. METHODS: We conducted a retrospective cohort study in the Greater Cincinnati Northern Kentucky region over an 18-month period (July 2019 to December 2020). All acute ischemic stroke events were captured. The modified Rankin Scale scores were determined at discharge, 3, 6, and 12 months for patients who survived the index event. We studied the association between Black race and longitudinal modified Rankin Scale (across all time points) with mixed-effects ordinal regression, initially adjusting for age, sex, and time since stroke. Hierarchical regression was used to sequentially adjust for stroke severity and management, premorbid health, and social determinants. RESULTS: Among 2796 patients with acute ischemic stroke (mean age, 69.0; 31% Black; 52% female), 2537 survived and were included (mean age, 68.4; 32% Black; 52% female). Black race was associated with a worse longitudinal modified Rankin Scale score (cOR, 2.61 [95% CI, 1.89-3.60]). Excluding patients with recurrent events did not change this association (cOR, 2.69 [95% CI, 1.92-3.78]). Adding variables reflecting initial stroke severity and management partly attenuated the association (cOR, 1.92 [95% CI, 1.43-2.60]). Adding variables reflecting premorbid health further attenuated the association (cOR decreased to 1.43 [95% CI, 1.09-1.87]). The remaining association between Black race and the modified Rankin Scale score was fully attenuated by social determinants, with cOR, 1.09 (95% CI, 0.80-1.47). There was no interaction between race and time since stroke. CONCLUSIONS: Starting at discharge and persisting out to 12 months, acute ischemic stroke functional outcomes are worse among Black individuals. These disparities are significantly attenuated by clinical factors and social determinants; future studies should explore whether the social determinants can be intervened upon in the recovery period.