1. Department of Medicine, Sorlandet Hospital Kristiansand, Kristiansand, Norway
2. Clinical Effectiveness Research Group, University of Oslo, Oslo, Norway
3. Clinical Effectiveness Research Group, Department of Transplantation Medicine, Oslo University Hospital, Oslo, Norway
4. Section for Colorectal Cancer Screening, Cancer Registry of Norway, Oslo, Norway
5. Department of Medicine, Telemark Hospital Skien, Skien, Norway
6. Department of Medicine, Vestre Viken Hospital Trust, Gjettum, Norway
7. Department of Medicine, Vestfold Hospital Trust, Tønsberg, Norway
8. Department of Pathology, Sorlandet Hospital Kristiansand, Norway