Prevalence of stroke and transient ischemic attacks in the Atherosclerosis Risk in Communities (ARIC) study.

The Atherosclerosis Risk in Communities (ARIC) study is a population-based observational study of randomly sampled, census-based populations in four locations within the United States. The study was designed to determine whether there are regional differences in incidence, prevalence, and mortality rates from cardiovascular and cerebrovascular disease in populations aged 45 to 64 years. Both cohort examinations and community surveillance are included. In addition to a standardized transient ischemic attack (TIA) and stroke questionnaire and algorithm for determination of incidence and prevalence, B-scan ultrasonography is used to quantify the degree of atherosclerotic changes in the carotid artery. Initiated in late 1986, the first cohort evaluation was completed in early 1990. The third, which includes magnetic resonance imaging of the brain, is in progress and will be completed in 1996. Positive responses to the TIA/stroke questionnaire increase by decile of age, are greater in women than men, and are more frequent in African Americans than Caucasians. The baseline study using an algorithm for categorization of patient responses into vascular and other causes of TIA and stroke estimated prevalence of 5.5% in African Americans and 6.3% in Caucasians.