Studies will be conducted on the cumulative lifetime Medicare costs of individuals from four Chicago population cohorts from which prior risk factor data are available. One cohort is from the Western Electric Company Study, with 2107 men who were 40-56 when the follow up began in 1957. For this group a physical exam, ECG and cholesterol measures are available along with data from a quantitative diet history conducted at that time assessing 28 days of intake. It is not clear whether the men themselves or their wives provided this information. Repeat measures are available, but attention is paid to their use in the analyses. Also, information on the availability of the quantitative information at the food level is not provided. Two cohorts are from the Peoples Gas Company Study, one with 1594 men aged 40-59 in 1958 and the second with 1609 men aged 25-39 in 1959 . From both cohorts a total of 1802 men are, based on their ages, currently Medicare eligible.The fourth cohort is the Chicago Heart Disease Detection Association Project (CHA) based on an initial survey of 39,573 men and women conducted in 1967-1973 on whom dietary data are not available.