1. Department of Research, Telemark Hospital Skien, Skien, Norway
2. University of Oslo, Oslo, Norway
3. Cancer Registry of Norway, Oslo, Norway
4. Department of Medicine, Telemark Hospital Skien, Skien, Norway
5. Institute of Clinical Medicine, University of Tromsø, Tromsø, Norway
6. Department of Medicine, University Hospital, North Norway, Tromsø, Norway
7. Institute of Health and Society, University of Oslo, Oslo, Norway
8. Department of Medicine, Sørlandet Hospital Kristiansand, Kristiansand, Norway
9. Department of Transplantation Medicine, Oslo University Hospital Rikshospitalet and Faculty of Medicine, University of Oslo, Oslo, Norway
10. Department of Medicine, Telemark Hospital Notodden, Notodden, Norway
11. Department of Gastroenterology, Oslo University Hospital, Oslo, Norway
12. Department of Medicine, Helse Fonna Hospital Trust, Haugesund, Norway
13. Department of Gastroenterology, Østfold Hospital Trust, Kalnes, Norway
14. Department of Medicine, Vestre Viken Hospital Trust, Bærum, Norway
15. Department of Medicine, Telemark Hospital Kragerø, Kragerø, Norway
16. Department of Medicine, Vestfold Hospital, Tønsberg, Norway