The project includes surveillance of about 80,000 men and women in each community and repeated examinations of representative cohorts of about 4,000 persons in each community. The racial composition of one cohort is black, while the other three cohorts reflect the ethnic and racial composition of the communities from which they are drawn. All cohort participants receive 3 yearly clinical examinations and provide an annual update on their medical histories.
Atherosclerosis is measured by ultrasonography.
Investigators also monitor hospital records and death certificates in an attempt to determine cause of death.