1. From the Departments of Vascular Medicine (G.K.H., A.G.H., W.P., P.R., E.d.G., J.J.P.K., J.A.K.) and Clinical Epidemiology and Biostatistics (B.A.H., A.H.Z.), Academic Medical Center, Amsterdam, the Netherlands, and Department of Medicine (A.S.), University Medical Centre Nijmegen, Nijmegen, the Netherlands.