1. Department of Community Medicine, UiT The Arctic University of Norway , PO Box 6050 Langnes, N-9037 Tromsø , Norway
2. University Hospital of North Norway , Postboks 100, 9038 Tromsø , Norway
3. Department of Clinical Science, University of Bergen , Bergen , Norway
4. Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University , Melbourne , Australia
5. Centre for Sami Health Research, Department of Community Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway , Tromsø , Norway
6. Department of Clinical Medicine, UiT The Arctic University of Norway , Tromsø , Norway
7. Department of Molecular and Clinical Medicine, Sahlgrenska Academy, Institute of Medicine, University of Gothenburg , Gothenburg , Sweden
8. Institute of Clinical Medicine, University of Oslo , Oslo , Norway
9. Akershus University Hospital, Lørenskog , Oslo , Norway