Incidence Rates of Stroke for Blacks and Whites: Preliminary Results from the Greater Cincinnati/Northern Kentucky Stroke Study
Background: We have previously estimated the stroke incidence rate in the US to be 731,000/yr using data from blacks in Cincinnati and whites in Rochester, MN. We present preliminary stroke incidence rates using data from white and black residents of the Greater Cincinnati metropolitan area. Methods: All strokes between 1/1/93–6/30/94 for blacks and 7/1/93–6/30/94 for whites were identified by surveillance of ICD-9 discharge codes from hospitals (430–438, 1o or 2o), coroner’s records, and surveillance of outpatient settings including emergency departments, hospital based outpatient clinics, family practice centers, and a random sampling of primary care offices and nursing homes. More than 17,000 potential stroke/TIA events were screened. During abstraction, research nurses determined stroke subtype, using strict criteria. Overall agreement on stroke subtype and diagnosis between study nurses and physicians is 87% (κ = 0.71). The incidence rates per 100,000 for stroke were calculated and standardized to the 1990 total U.S. population. Results: Rates of first-ever stroke among blacks were consistently higher than rates for whites for all stroke subtypes (Table). The overall rate of first-ever and recurrent stroke was 291 per 100,000. Conclusion: Based on these incidence rates, derived from a large, population-based study, we estimate that 760,000 strokes will occur in the US in the year 2000.