1. From the Departments of Public Health (M.P.v.d.M., I.L.V., S.L.G., M.v.B.), Gastroenterology and Hepatology (E.J.K.), and Internal Medicine (E.J.K.), Erasmus Medical Centre, University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, the Netherlands; Department of Gastroenterology and Hepatology (E.D.) and Department of Radiology (J.S.), Academic Medical Center, Amsterdam, the Netherlands.