Population-based cohort studies: still relevant?

This commentary discusses the question whether observational epidemiology studies using a population-based cohort design continue to make an impact on the prevention and treatment of cardiovascular disease. Although these studies are large and comprehensive, have they advanced from the early recognition of traditional risk factors to become relevant in the current complex research environment? Five themes are discussed: 1) their role in scientific discovery, including in the context of clinical trials' role in interventional research; 2) their value in encompassing diverse ethnic and age groups to remain relevant to the changing diversity of the United States; 3) the research potential of combining these datasets into large consortia; 4) the ability to use advances in biomedical research technologies; and 5) the recognition that these are national resources that allow outside research community to analyze the collected data and to originate novel ancillary studies. The National Heart, Lung, and Blood Institute longitudinal cohort studies offer opportunities that hold great promise in improving evaluation of personal risk, identifying mechanisms of disease, and directing potential targets for behavior and medical interventions.