1. Department of Internal Medicine, Stavanger University Hospital, Stavanger, Norway.
2. Department of Clinical Medicine, University of Bergen, Bergen, Norway.
3. Department of Transplantation Medicine, Oslo University Hospital, Oslo, Norway.
4. Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway.
5. Norwegian Renal Registry, Oslo, Norway.
6. Department of Medical Biochemistry, Stavanger University Hospital, Stavanger, Norway.
7. Institute of Health and Society, University of Oslo, Oslo, Norway.