Stroke incidence decreasing in whites, unchanged in blacks

First-ever stroke rates have been declining in whites but not in blacks, results from a study suggested.

Researchers from Cincinnati analyzed stroke incidence among 1.3 million residents within the Greater Cincinnati/Northern Kentucky population using information from local hospitals.

They determined that there were 1,942 first-ever strokes among residents aged 20 years or older from the five-county area from 1993 to 1994; 2,041 in 1999; and 1,921 in 2005, according to the researchers.

In whites, the incidence of all first-ever strokes significantly decreased in 2005 (189 per 100,000) compared with prior study periods (214 in 1993 to 1994; 215 in 1999; P<.001). “This was driven by a decrease in ischemic stroke incidence, because the hemorrhagic stroke incidence remained stable,” the researchers wrote. However, similar declines were not observed among blacks.

During every study period, blacks had a higher prevalence of hypertension, diabetes and current smoking and had a similar prevalence of hypercholesterolemia, prior stroke and heart disease when compared with whites. The inclusion of cases ascertained in out-of-hospital settings did not change these findings, according to the researchers.

These findings suggest that “the well-described substantial racial disparity in stroke incidence is worsening,” the researchers wrote.

Additional findings suggested that whites were more likely to report aspirin use than blacks in all three study periods, and there were no significant racial differences in reported use of lipid-lowering agents. Regarding temporal trends, both blacks and whites reported significantly increased rates of aspirin and lipid-lowering agent use.

“There is still much work to be done to understand racial disparities and temporal trends in stroke incidence,” the researchers wrote. “Population-based studies of temporal trends in stroke incidence rates are critical for providing a report card of our overall progress in primary stroke prevention as well as our efforts to reduce the continuing disparity in incidence rates between black and white populations in the United States.”

Kleindorfer DO. Stroke. 2010;doi:10.1161/strokeaha.109.575043.