Affiliation: | (1) Department of Surgery, VU medical centre, Amsterdam, The Netherlands;(2) Department of Clinical Epidemiology and Biostatistics, VU medical centre, Amsterdam, The Netherlands;(3) Department of Surgery, Academisch Medisch Centrum, Amsterdam, The Netherlands;(4) Department of Surgery, Central Teaching Hospital, Bergen University, Forde, Norway;(5) Department of Surgery, Waterland Hospital, Purmerend, The Netherlands;(6) Department of Surgery, Hospital Clinic, Barcelona, Spain |