1. Department of Surgery, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
2. Departments of Surgery, Medical Centre Alkmaar, Alkmaar, The Netherlands
3. Spaarne Gasthuis Hospital, Hoofddorp, The Netherlands
4. Clinical Research Unit, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
5. Spaarne Gasthuis Hospital, Haarlem, The Netherlands
6. Department of Surgery, Onze Lieve Vrouwe Gasthuis West, Amsterdam, The Netherlands
7. Meander Medical Centre, Amersfoort, The Netherlands
8. Albert Schweitzer Hospital, Dordrecht, The Netherlands
9. Ziekenhuisgroep Twente Hospital, Almelo, The Netherlands
10. Academic Medical Centre, University of Amsterdam, Amsterdam
11. VU University Medical Centre, Amsterdam
12. Kennemer Gasthuis Hospital, Haarlem
13. Spaarne Hospital, Hoofddorp
14. Saint Lucas Andreas Hospital, Amsterdam
15. Meander Medical Centre, Amersfoort
16. Máxima Medical Centre, Veldhoven
17. Onze Lieve Vrouw Gasthuis Hospital, Amsterdam
18. Gelre Hospital, Apeldoorn
19. BovenIJ Hospital, Amsterdam
20. Red Cross Hospital, Beverwijk
21. Albert Schweitzer Hospital, Dordrecht/Zwijndrecht
22. Tergooi Hospital, Hilversum
23. Ziekenhuisgroep Twente Hospital, Almelo/Hengelo
24. Westfriesgasthuis Hospital, Hoorn
25. Ikazia Hospital, Rotterdam
26. Erasmus University Medical Centre, Rotterdam
27. Saint Franciscus Hospital, Rotterdam
28. Slotervaart Hospital, Amsterdam
29. Reinier de Graaf Gasthuis Hospital, Delft
30. Flevo Hospital, Almere
31. Saint Antonius Hospital, Nieuwegein
32. Julius Centre for Health Sciences and Primary Care, University Medical Center, Utrecht