1. From the Departments of Epidemiology & Biostatistics (M.H., A.I.d.S., J.C.M.W., A.H., M.M.B.B.) and Neurology (M.H., P.J.K.), Erasmus Medical Center Rotterdam, and Julius Center for General Practice and Patient Oriented Research (M.L.B., A.I.d.S., D.E.G.), University Medical Center Utrecht, the Netherlands.