1. Department of Surgery Maastricht University Medical Centre+ Maastricht The Netherlands
2. Care and Public Health Research Institute (CAPHRI) Maastricht University Medical Center+ Maastricht The Netherlands
3. Department of Surgery Raigmore Hospital Inverness UK
4. Department of Surgical Proctology Proktologische Praxis Kiel, Kiel Germany
5. Department of Emergency and Organ Transplantation University of Aldo Moro of Bari Bari Italy
6. Surgical Department A Odense University Hospital Odense C Denmark
7. Clinique Saint Antoine Nice France
8. Department of Family Medicine/General Practice Research Institute CAPHRI Maastricht University Maastricht The Netherlands