1. Clinic for Cancer, Surgery and Transplantation, Oslo University Hospital, Rikshospitalet, 0424 Oslo, Norway
2. Department of Nursing Science, University of Oslo, 0318 Oslo, Norway
3. Faculty of Medicine, Department of Public Health and Primary Health Care, University of Bergen, 5020 Bergen, Norway
4. NOVA-Norwegian Social Research, 0208 Oslo, Norway
5. Epi-Gen-Institute, Campus Ahus, Akershus University Hospital, 1478 Lorenskog/Faculty of Medicine, University of Oslo, 0318 Oslo, Norway
6. Department of Health Sciences, University of Oslo, 0317 Oslo, Norway