Abstract T MP63: Temporal Trends in Stroke Incidence Over the Past Twenty Years: Stroke Incidence Has Stabilized, Racial Disparity is not Improving

Abstract

Introduction: We previously reported that the incidence of stroke was decreasing for whites but stable for blacks from 1993/94 to 2005. We sought to describe recent temporal trends and racial disparities in stroke incidence within our large, bi-racial population, by including a more recent study period. Methods: The Greater Cincinnati/Northern Kentucky region includes two southern Ohio and three Northern Kentucky counties on the Ohio River, a population of 1.3 million. Our study ascertained all hospitalized strokes that occurred in the population between 7/1/93 and 6/30/94 and in calendar years 1999, 2005, and 2010. For 2010, nursing review of medical records is complete but physician review is not; thus, rates for 2010 (calculated using a weighted estimation for events not completely reviewed) are preliminary. The denominator for the calculation of incidence rates (in those aged >20 years) was estimated from the U.S. Census Bureau website (www.census.gov). The 95% confidence intervals (CI) for the incidence rates were calculated assuming a Poisson distribution. Rates are age, gender, and race adjusted, as appropriate, and standardized to the 2000 U.S. population. Results: Stroke incidence rates stratified by subtype, race, and study period are presented in the Table. We project that stroke incidence did not significantly change in 2010 vs. 2005 for either blacks or whites, regardless of stroke subtype. Blacks have a substantially higher incidence of stroke compared with whites in all study periods. Discussion: In contrast to the trend seen from 1993-94 to 2005, there was no further decline of stroke incidence in whites in 2010, a disappointing finding of great public health significance. Stroke incidence in blacks remains unchanged over all periods. The substantial black > white racial disparity in stroke incidence has not changed over time. Further study is needed to understand and eventually reduce these racial disparities.