Stroke in a Biracial Population

Abstract

Background and Purpose— Excess mortality resulting from stroke is an important reason why blacks have higher age-adjusted mortality rates than whites. This observation has 2 possible explanations: Strokes occur more commonly among blacks or blacks have higher mortality rates after stroke. Our population-based epidemiological study is set in the Greater Cincinnati/Northern Kentucky region of 1.31 million people, which is representative of the US white and black populations with regard to many demographic and socioeconomic characteristics. Methods— Hospitalized cases were ascertained by International Classification of Diseases (ninth revision) discharge codes, prospective screening of emergency department admission logs, and review of coroner’s cases. A sampling scheme was used to ascertain cases in the out-of-hospital setting. All potential cases underwent detailed chart abstraction by study nurses, followed by physician review. Race-specific incidence and case fatality rates were calculated. Results— We identified 3136 strokes during the study period (January 1, 1993, to June 30, 1994). Stroke incidence rates were higher for blacks at every age, with the greatest risk (2- to 5-fold) seen in young and middle-aged blacks (<65 years of age). Case fatality rates did not differ significantly in blacks compared with whites. Applying the resulting age- and race-specific rates to the US population in 2002, we estimate that 705 000 to 740 000 strokes have occurred in the United States, with a minimum of 616 000 cerebral infarctions, 67 000 intracerebral hemorrhages, and 22 000 subarachnoid hemorrhages. Conclusions— Excess stroke-related mortality in blacks is due to higher stroke incidence rates, particularly in the young and middle-aged. This excess burden of stroke incidence among blacks represents one of the most serious public health problems facing the United States.