1. Division of Digestive Surgery and Urology, Turku University Hospital, Turku, Finland
2. Department of Surgery, University of Turku, Turku, Finland
3. Department of Surgery, Helsinki University Hospital, Helsinki, Finland
4. Department of Biostatistics, University of Turku and Turku University Hospital, Turku, Finland
5. Department of Surgery, Oulu University Hospital, Oulu, Finland
6. Medical Research Center Oulu, University of Oulu, Oulu, Finland
7. Department of Gastroenterology and Alimentary Tract Surgery, Tampere University Hospital, Tampere, Finland
8. Faculty of Medicine and Health Technology, University of Tampere, Tampere, Finland
9. Department of Surgery, Kuopio University Hospital, Kuopio, Finland
10. Department of Surgery, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
11. Department of Surgery, Seinäjoki Central Hospital, Seinäjoki, Finland
12. Department of Surgery, Mikkeli Central Hospital, Mikkeli, Finland
13. Wellbeing Services County of Central Finland, Hospital Nova of Central Finland, Jyväskylä, Finland
14. Department of Surgery, Rovaniemi Central Hospital, Rovaniemi, Finland
15. Department of Hospital Hygiene and Infection Control, Turku University Hospital, Turku, Finland
16. Department of Surgery, Satakunta Central Hospital, Pori, Finland