1 Clinical Effectiveness Research Group, Institute of Health and Society, University of Oslo, Oslo, Norway; Clinical Effectiveness Research Group, Department of Transplantation Medicine, Oslo University Hospital, Oslo, Norway; Section of Oncology, Drammen Hospital, Vestre Viken Hospital Trust, Drammen, Norway.
2 Clinical Effectiveness Research Group, Institute of Health and Society, University of Oslo, Oslo, Norway; Department of Gastroenterology, Hepatology and Clinical Oncology, Center of Postgraduate Medical Education, Warsaw, Poland.
3 Clinical Effectiveness Research Group, Institute of Health and Society, University of Oslo; Clinical Effectiveness Research Group, Department of Transplantation Medicine, Oslo University Hospital, Oslo, Norway.