1. Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, New York City (B.L.V., J.S., O.W., M.S.V.E., A.K.B.).
2. Department of Epidemiology (B.L.V., M.S.V.E., A.K.B.), Columbia University Irving Medical Center, New York.
3. Department of Biostatistics (X.C.), Columbia University Irving Medical Center, New York.
4. Department of Emergency Medicine (B.P.C.), Columbia University Irving Medical Center, New York.
5. Department of Epidemiology and Biostatistics, Temple University College of Public Health, Temple University, Philadelphia, PA (E.R.K.).