The CHDS researches the way that health and disease are passed on in families, looking at genes as well as social, personal, and environmental surroundings. Data was collected from 15,000 families who were members of the Kaiser Foundation Health Plan in Oakland between 1959 and 1967 and who voluntarily enrolled when a woman first thought she was pregnant. Researchers may apply to use the data files. CHDS is a project of the Public Health Institute and is supported with funds from the National Institutes of Health.