1. Danish Hernia Database, Køge Hospital, Køge, Denmark
2. Department of Surgery, Køge Hospital, Køge, Denmark
3. Section for Surgical Pathophysiology, Rigshospitalet, Copenhagen University, Copenhagen, Denmark
4. Department of Gastroenterology, Hvidovre University Hospital, Hvidovre, Denmark
5. Danish National Board of Health, Departments of Surgical Gastroenterology, Aarhus, Denmark
6. Aarhus University Hospital, Aarhus, Denmark
7. Herlev University Hospital, Herlev, and Departments of Surgery, Denmark
8. Horsens Hospital, Horsens, Denmark
9. Bispebjerg University Hospital, Copenhagen, Denmark