The principles underlying the chronic disease data bank model are straight-forward: (1) the purpose of medical care is to improve patient outcomes; (2) patient outcomes in contemporary developed societies are overwhelmingly linked to chronic illnesses and degenerative processes and will become increasingly so; (3) such outcomes have multiple determinants including the psychological and social, as well as the biologic; (4) outcome antecedents (risk factors) may precede clinical illness by years or decades; and (5) these complex characteristics require for their study (a) computer aid and (b) longitudinal data. The chronic disease data bank provides an important resource, available to many investigators, for examination of the complex set of clinical and policy questions arising with long-term illness and addressing the questions of lifetime health. The chronic disease data bank consecutively enrolls eligible subjects, follows them for life, and amasses time-oriented, multidisciplinary data including clinical findings, medical history, demographics, treatments, resource utilization and disease outcomes, and assessing both the quality of life and its duration. Analyses are longitudinal and time-series in type, examining changes in trends and tempo of the disease, and are focused upon long-term outcomes. Outcomes are regularly and carefully assessed, and include the outcome dimensions of death, disability, discomfort, iatrogenic toxicity, and dollar cost. Specific studies address the description of the disease from biologic, demographic, economic, and social viewpoints, identify the factors associated with good and bad outcomes, and assess the effects of treatment, both good and ill. The clinical and policy goals are focused upon delaying transitions from more benign disease states to more serious ones, thus improving both longevity and the quality of life. The time is appropriate to consider generalization of the chronic disease data bank model to the usual clinical care situation, with large rewards in improvement of the quality of care. The traditional medical record lacks systematic documentation of end results and of important covariates related to health risks. As such, it cannot readily be used to assess the ultimate quality of care and to establish a feedback loop to change behaviors and thereby improve outcomes. It is weak where the chronic disease data bank is strong. The technology is transferable.