Given that mortality risks at advanced ages (over 85) due to circulatory diseases have decreased recently and that it is likely that the effects of risk factors change with age, it is important to study the age dynamics of circulatory disease and circulatory risk factors in elderly populations. Analysis of chronic disease risks, however, is complicated at advanced ages because of the prominence of natural age increases in risk and the rapid rate at which health status changes at those ages. As a consequence, to identify the effects of putative risk factors at advanced ages one must employ appropriate analytic procedures to isolate risk factor effects from aging dynamics. Special risk assessment procedures developed to represent age-related biological processes aare applied to an analysis of circulatory disease risk in a study population with a mean age at study entry of over 70 years--the first Duke University Longitudinal Study of Aging population.