The Coronary Artery Risk Development in Young Adults (CARDIA) study was established in 1985 by the National Heart, Lung, and Blood Institute (NHLBI) to study the distribution and evolution of cardiovascular disease risk beginning in young adulthood in four U.S. communities (Birmingham, AL; Chicago, IL; Minneapolis, MN; and Oakland, CA) (http://www.cardia.dopm.uab.edu/). The original cohort (n=5,115) was selected to have approximately the same number of participants in subgroups of age (18-24 and 25-30), sex, race (black and white), and education (high school or less and more than high school) within each community. Participants were sampled from the total population, selected census tracts or, in the case of one center, the membership of a large health plan. The baseline examination was conducted over a 14-month period during 1985-86. Nine follow-up examinations have been conducted approximately every 2-5 years (1987-88, 1990-91, 1992-93, 1995-96, 2000-01, 2005-06, 2010-11, 2015-16, 2020-22). Cohort members are also contacted every six months to obtain information on vital status and current residence. Every other six-month contact also includes the collection of information on major illness or injury and hospitalizations occurring between contacts to identify clinical events of interest.