Reasons underlying racial differences in stroke incidence and mortality.

A lthough there has been a significant decline in overall stroke mortality rates since the 1950s, age-adjusted stroke death rates have remained higher in blacks than in whites through 2008. 1 The Table shows the 2009 stroke death rates per 100 000 according to age and sex for blacks and whites. The relative excess in deaths from stroke among blacks compared with whites is most marked in the population aged <65 years, in which, for example, there is a black/ white mortality ratio of 3.7 among men aged 45 to 54 years. The black/white mortality ratio decreases with age in both sexes until ages ≥85 years, when death rates in blacks are lower than in whites. Differences between whites and other racial and ethnic groups in the United States are important but less marked. In 2008, stroke death rates were lowest in American Indians/Alaska natives (24.0 in women and 24.5 in men per 100 000.) 1 Stroke death rates were similar in Hispanic and Asian/Pacific Islanders, both with rates lower than those in whites. 1 Complicating the discussion of racial and ethnic differences in stroke mortality is that the race groups of whites, blacks, Asian/Pacific Islander, and American Indian/ Alaska Native include persons of Hispanic and non-Hispanic origin, and the Hispanic category includes persons across all race groups. Also, death rates are known to be underestimated for Hispanics, Asian/Pacific Islanders, and American Indians/ Alaska Natives for whom data are likely less reliable. 2 The initial concerns about black–white disparities in stroke were recognized in the 1970s based on mortality statistics. 3,4 These concerns were reinforced by 3 population-based cohort studies of stroke incidence reporting rates observed during the 1960s that also showed similar black–white disparities in incident stroke risk. 5–7 There are several more current epidemiological studies that provide insights to black–white differences in stroke incidence across a broad age spectrum and in different regions of the United States, with some also providing insights to the risk factors potentially contributing to the excess stroke risk in blacks compared with whites. 8–17 The higher prevalence of risk factors in blacks, particularly hypertension and diabetes mellitus, are perhaps the most widely recognized contributing factors. Data from 13-year follow-up (through 1987) of the first National Health and Nutrition Examination Survey Epidemiologic Follow-up Study showed that the risk factors of age, sex, education, blood pressure treatment group (normotensive, controlled hypertensive, hypertensives receiving medication, and …