1. Department of Medicine, Sorlandet Hospital Kristiansand, Kristiansand, Norway
2. Department of Internal Medicine, Section of Gastroenterology, Bærum Hospital, Vestre Viken Hospital Trust, Rud, Norway
3. Department of Medicine, Vestfold Hospital Trust, Tonsberg, Norway
4. Department of Medicine, Telemark Hospital Skien, Skien, Norway
5. Department of Medicine, Sorlandet Hospital, Arendal, Norway
6. Department of Medicine, Østfold Hospital, Fredrikstad, Norway
7. Department of Medicine, Innlandet Hospital Elverum, Elverum, Norway
8. Institute of Health and Society, Department of Management and Health Economy, University of Oslo, Oslo, Norway