1. From the Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Conn (S.S.R.); Division of Neurology, Department of Medicine, School of Medicine (A.R.H.), and Department of Epidemiology, School of Public Health (H.A.T., W.D.R.), University of North Carolina at Chapel Hill; and Division of Epidemiology and Clinical Application, National Heart, Lung, and Blood Institute, Bethesda, Md (L.S.C.).