The effectiveness of the program was evaluated by population surveys in Monterey, Salinas, Modesto, and San Luis Obispo but not Santa Monica and by a morbidity and mortality surveillance system. In the initial year of the survey in 1979-1980, approximately 600 people in each community visited the survey center. This comprised the first independent sample of the community. After an average of 15 months, these same individuals returned to the survey center for a follow-up evaluation. This cohort sample has been studied every other year for five surveys to determine the process of change in cardiovascular risk and related behaviors over time. Five randomly-selected independent samples have been surveyed to study cross-sections of the community over time. Questionnaires and dietary measures were the chief sources of data on health-related behaviors. The questionnaire contained components on: demographic measures; attitude and opinion measures; health knowledge assessment related to prevention of heart disease and stroke; stress behavior; diet, nutrition, and weight behavior; smoking behavior; physical activity behavior; communication media use; and medical history including medication use. A random 40 percent of the initial sample completed a 24-hour dietary recall which was re-administered in the fourth cohort survey and was also administered to a 50 percent random sample of the fourth independent survey. Biological measurements consisted of height and weight, blood pressure, resting heart rate, plasma thiocyanate, total cholesterol, triglycerides and cholesterol content of lipoprotein subfractions, expired air carbon dioxide, urinary sodium, potassium and creatinine, and an exercise test. Data were also collected on plasma apolipoprotein A-1 and B and on high density lipoprotein subfractions 2 and 3. A comprehensive dietary assessment was also conducted.