Racial differences in the incidence of intracerebral hemorrhage: Effects of blood pressure and education

Objective: To determine the relative risk (RR) of intracerebral hemorrhage (ICH) among African Americans compared with that among whites. Methods: Data from the First National Health and Nutrition Examination Survey Epidemiologic Follow-up Study were used to determine the incidence of ICH (n = 78) in 10,851 whites and 1,802 African Americans during a 20-year follow- up period. Cox proportional hazards analyses were used to determine the RR of ICH among African Americans compared with that among whites. Results: The estimated annual incidence of ICH was 50 per 100,000 among African Americans and 28 per 100,000 among whites. The age- and sex-adjusted RR for ICH among African Americans was 1.9 (95% confidence interval [CI], 1.1 to 3.2). With the addition of systolic blood pressure and educational attainment to the Cox proportional hazards model, the RR decreased to 1.6 (95% CI, 0.9 to 2.7). The adjustment for additional cerebrovascular disease risk factors did not change this risk estimate appreciably. Conclusions: Compared with whites, African Americans have a twofold increased risk for ICH. Most of this risk may be explained by differences in educational attainment and systolic blood pressure. Unless additional efforts are undertaken to reduce racial differences in the prevalence of stroke risk factors, mainly systolic blood pressure and socioeconomic status, the African American-white disparities in the risk for ICH will likely continue.