1. Centre for Digestive Diseases, Division of Hepatology, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden;
2. Department of Transplantation Medicine, Section for Gastroenterology and Norwegian PSC Research Center, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital Rikshospitalet, Oslo, Norway;
3. Department of Gastroenterology, Akershus University Hospital, Lørenskog, Norway;
4. Institute of Clinical Medicine, University of Oslo, Oslo, Norway;
5. Transplant Institute, Sahlgrenska University Hospital and Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden;
6. Department of Surgery and Liver Transplantation, Rigshospitalet, Copenhagen, Denmark;
7. Department of Surgery, University of Helsinki and Helsinki University Hospital, Helsinki, Finland;
8. Unit of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden