Abstract TMP58: Preliminary Population-Based Temporal Trends in Stroke Incidence: Racial Disparity and Stroke Incidence From 1993-2015

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 2010 and preliminary data from 2015. 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 representative of the US population in terms of sociodemographics and percent black race. 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, 2010 and 2015. For 2015, nursing review of medical records is complete but physician review is not; thus 2015 rates 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, sex, and race adjusted, as appropriate, and standardized to the 2010 U.S. population. Results: First-ever 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 2015 vs. 2010 for either blacks or whites, regardless of stroke subtype. Blacks have a substantially higher incidence of stroke compared with whites in all study periods, without significant change in disparity over time. Discussion: In contrast to the significant decline in stroke incidence among whites from 1993-94 to 2005, we did not observe a statistically significant decrease in 2010 and 2015. This may be due to true stabilization of rates over time, or less statistical power to detect smaller declines. The substantial black/white racial disparity in stroke incidence has not changed over time.