1. From the Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA (I.Y.S.), Columbia University, New York, NY.
2. Department of Neurology, Vagelos College of Physicians and Surgeons (M.S.V.E., A.K.B.), Columbia University, New York, NY.
3. Department of Epidemiology, Mailman School of Public Health (M.S.V.E., A.K.B.), Columbia University, New York, NY.