1. Department of Rheumatology
2. Institute of Clinical Medicine, University of Oslo, Oslo, Norway
3. Department of Rheumatology, Haukeland University Hospital, Bergen, Norway
4. Department of Rheumatology, University Hospital of North Norway, Tromso, Norway
5. Department of Rheumatology, Hospital of Southern Norway, Kristiansand, Norway
6. Norwegian National Advisory Unit of Pregnancy and Rheumatic Diseases, Department of Rheumatology, Trondheim University Hospital, Trondheim, Norway
7. Institute of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Norwegian University of Science and Technology, Trondheim, Norway; and
8. Department of Rheumatology, Lillehammer Hospital, Lillehammer, Norway
9. Oslo Centre for Biostatistics and Epidemiology, Research Support Services
10. Department of Respiratory Medicine, and
11. Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway