Affiliation: | 1. Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina;2. Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina;3. National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, Maryland;4. Cardiovascular Division, Brigham and Women''s Hospital, Harvard University; Boston, Massachusetts;5. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland |