A comparison of stroke risk factors in patients enrolled in stroke prevention trials

The high prevalence of stroke risk factors may explain, in part, the high incidence of stroke in African Americans. To further investigate the role of stroke risk factors, we compared stroke risk factor profiles of patients in the African-American Antiplatelet Stroke Prevention Study (AAASPS) with those in other stroke prevention studies in which the enrollees were predominately white. The baseline characteristics of the AAASPS enrollees obtained from an interim AAASPS database of 1,087 patients from 65 centers in the U.S. between December 1995 and June 1999 was compared to the baseline characteristics of 53,293 predominantly non-African American patients enrolled in 23 other stroke prevention studies (pNAA). Percentages were reported for qualitative characteristics, and means and standard deviations (SDs) for quantitative characteristics. For selected qualitative characteristics, 95% confidence intervals were given for population percentages in each study. The comparison of baseline characteristics showed that hypertension was more prevalent in AAASPS (84% [95% CI 82.2, 86.61) compared to pNAA trial patients (range of 27% to 67%). Diabetes mellitus was more common in AAASPS (39.1%) compared to pNAA trial patients (17.1%). Cardiac disease, however, was less common in AAASPS than in pNAA trials. The frequency of baseline characteristics of AAASPS patients is different from those of pNAA studies. Risk factor profiles are important as they may help to predict stroke subtype and outcome. Furthermore, the differences in baseline characteristics may portend differences in response to treatment and incidence of adverse events.