Abstract Body: Background: Black individuals are at a higher risk of stroke, but little is known about racial disparities in functional outcome. Using a representative population-based study, we examined disparities in outcome over multiple timepoints in the first year after acute ischemic stroke (AIS).
Methods: We ascertained all hospitalized AIS events in the Greater Cincinnati Northern Kentucky region from July 2019-December 2020 (Black individuals) and January 2020-December 2020 (White individuals). Potential cases were identified by ICD codes, abstracted, and physician adjudicated. Only patients who survived their initial hospitalization were included. Using a validated approach, modified Rankin Scale (mRS) was determined retrospectively at discharge, 3 months, 6 months, and 1-year post-stroke. Mixed effect ordinal regression was used to investigate the effect of Black race on functional outcome, after adjustment for relevant factors. We collapsed mRS scores of 5 and 6 into one category for the ordinal shift analyses due to the small number of patients with an mRS of 5. A race:time interaction term was considered to assess whether the race-based differences in functional outcome varied by timepoint. Missing data was handled via full information maximum likelihood.
Results: Over the study period, we identified 2541 AIS survivors, of whom 816 (32%) were Black and 1306 (51%) were women (Graphic 1). Unadjusted distributions of mRS scores over 1 year of follow-up are shown in Graphic 2. At 12 months, 25.4% of White individuals (434/1707) and 21.2% of Black individuals (169/799) had an mRS of 0 or 1. When adjusted for age and sex, Black race was associated with a shift towards worse ordinal mRS (Graphic 3, cOR 1.48, 95% CI 1.30-1.68). When other potential confounders were added to the model, the effect of Black race was attenuated but remained significant (cOR 1.16, 95% CI 1.02-1.31). There was no significant interaction between Black race and time after stroke in either model (0.10 and 0.09, respectively).
Conclusions: Using one of the first population-based studies of long-term post-stroke functional outcomes in the U.S., we found that Black individuals experience worse functional outcomes, and this effect was incompletely attenuated when adjusted for comorbidities and initial management. Further research is needed to understand whether these disparities are driven by modifiable social determinants that impact stroke rehabilitation.