1. Department of General Practice, Amsterdam UMC, Location University of Amsterdam , Amsterdam, the Netherlands
2. Amsterdam Public Health, Research Programme Quality of Care, and Personalized Medicine , Amsterdam, the Netherlands
3. Department of Surgery, Onze Lieve Vrouwe Gasthuis , Amsterdam, the Netherlands
4. Department of Surgery, Dijklander Hospital , Hoorn, the Netherlands
5. Department of Surgery, Franciscus Gasthuis & Vlietland Hospital , Schiedam, the Netherlands
6. Department of Surgery, St. Antonius Hospital , Nieuwegein, the Netherlands
7. Department of Surgery, Amsterdam UMC, Location University of Amsterdam , Amsterdam, the Netherlands
8. Department of Surgery, Spaarne Gasthuis , Hoofddorp, the Netherlands