Risk Factor Surveillance: Population samples, aged 25-74 years, are recruited and measured for blood pressure, serum cholesterol, serum high density lipoprotein cholesterol, cigarette smoking, diet, physical activity, height, weight, health attitudes and beliefs, and coronary prone behavior. Surveys were completed in 1980-1982 and 1984-1985. The third survey conducted in 1990-1992 included the Willett Food Frequency Questionnaire and bioimpedance measurements. A nested case-control study using the 1980-1982 risk factor cohort examined the baseline cardiovascular disease risk factor differences between coronary heart disease in cases and controls.