Racial Differences In Intracerebral Hemorrhage Risk: The Reasons For Geographic And Racial Differences In Stroke Study (Regards)

Introduction: Intracerebral Hemorrhage (ICH) risk is higher in blacks vs whites in the U.S. especially at younger ages. We used the REGARDS study to determine what prospectively assessed factors may underlie black-white differences in ICH risk. Methods: REGARDS recruited black and white individuals aged 45+ in the U.S. to explain regional and racial differences in stroke risk. Cox models with an age*race interaction term estimated the age-dependent hazard ratio (HR) of black versus white individuals for ICH. The 95% confidence interval (CI) of the percent attenuation of the age-dependent hazard ratio (HR) from the baseline to the final model was calculated using bootstrapping. Results: Among 29,694 REGARDS participants (55% women; 41% black), 160 ICH events occurred over 254,440 person-years of follow-up (median 9.5 years). The point estimate for the black-white HR for ICH decreased with increasing age, being 4.8, 2.7, and 1.5 at ages 45y, 55y, and 65y (Table, Baseline Model). In a final model, the point ...