The incidence of blood clot-related strokes fell among whites in the Greater Cincinnati/Northern Kentucky area for the first time, according to long-term surveillance study representative of strokes in blacks and whites nationwide, reported in Stroke: Journal of the American Heart Association, Dallas.
However, there was no decrease in stroke rates among blacks.
Investigators found that the age-adjusted annual rate of ischemic stroke (those caused by a blood clot) resulting in hospitalization changed between 1999 and 2005 from:
- 189 to 167 per 100,000 overall, an 11.6% drop;
- 180 to 154 per 100,000 among whites, a 14.4% reduction;
- 263 to 275 per 100,000 among blacks, a 4.6% rise, but not a significant change.
The patterns remained the same when out-of-hospital strokes were included. During the same period, researchers found no change in the rate of hemorrhagic strokes (those caused by bleeding).
The likelihood of dying after an ischemic stroke remained steady over time and was similar in whites and blacks, about 10%, according to the report.
Researchers used data from the Greater Cincinnati/Northern Kentucky Stroke Study, which gathered information on all first strokes occurring in a five-county area with 1.3 million people. The counties include urban, suburban, and rural areas. It’s comparable to the nation in education, income, and in the percentage of blacks (18%), but does not include a substantial proportion of persons of Hispanic ethnicity (less than 3%).
The racial disparity could not be explained by differences in the occurrence and treatment of stroke risk factors. According to a telephone survey conducted in the study area, blacks were more likely than whites to have been diagnosed with risk factors such as high blood pressure and diabetes, but they were also more likely to be receiving treatment for these conditions.
The investigators are collecting 2010 data in their ongoing phase of their epidemiology of stroke project.
Stroke is the third leading cause of death in the United States and a leading cause of major disability in adults.
The study is supported by the National Institute of Neurological Disorders and Stroke.
[Source: American Heart Association]