The Bogalusa Heart Study continued to use a cross-sectional and longitudinal design with the general cross-sectional survey of approximately 3,700 Bogalusa children ages five to seventeen in 1988-1989 in the sixth screen and additional longitudinal studies to recall children in defined subgroups for more intensive evaluation. Half of the 12,000 participants screened since 1973 had been studied three or more times. There were several other cohort groups and studies. The Newborn-Infant Cohort Study was designed to describe distributions, inter-relationships, and trends through time for blood pressure, serum lipid and lipoprotein concentrations, dietary intake patterns, and anthropometric measurements. Four hundred and forty infants born between January 1, 1974 through June 30, 1975 were examined at birth, at six months, and yearly at ages one through four and at seven, ten and thirteen years for cardiovascular risk factor variables. The Post High School Study examined young adults ages 21 through 30 who previously were examined as children ages five through fourteen in the first Bogalusa Heart Study screening in 1973-1974. The population included approximately 4,603 young adults originally screened and any other children or adolescents examined for the first time in any subsequent surveys.