The JHS investigates the causes of cardiovascular disease in African-Americans. The study recruited approximately 5,300 African-American adults, aged 21 to 84 years, living in the urban and rural areas of three counties (Hinds, Madison and Rankin) that make up the Jackson, Mississippi, metropolitan statistical area (MSA) in the United States of America. This cohort includes a nested family cohort, recruited from among the relatives of “index participants” aged 35 to 84 years old who had at least two siblings and four other first-degree relatives residing in the recruitment area. Participants were assessed at recruitment between 2000 and 2004, and are followed up annually, as well as via medical records and death certificates.