1. From the Departments of Medicine (C.J.R., F.L., S.H., M.R.D.) and Neurology (R.L.S., B.B.-A.), Columbia University; the Departments of Epidemiology (C.J.R., R.L.S.), Sociomedical Science (B.B.-A.), and Biostatistics (Z.J.), Columbia University, Mailman School of Public Health; and Sergievsky Center (R.L.S.), College of Physicians & Surgeons, Columbia University, New York, NY.