1. From the Departments of Epidemiology and Biostatistics (C.T.M. van R., J.C.M.W., A.H., D.E.G) and Public Health (C.T.M. van R., H. van de M., J.P.M.), Erasmus University Medical School Rotterdam, Rotterdam, the Netherlands; and Julius Center for Patient Oriented Research (D.E.G.), Utrecht University Medical School, Utrecht, the Netherlands.