1. Copenhagen Centre for Arthritis Research, Centre for Rheumatology and Spine Diseases VRR, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
2. Musculoskeletal Rehabilitation Research UnitBispebjerg and Frederiksberg Hospitals, University of Copenhagen, Copenhagen, Denmark
3. Department of Clinical MedicineFaculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
4. Research Centre for Prevention and Health, Glostrup Hospital, University of Copenhagen, Copenhagen, Denmark
5. Section of Social MedicineDepartment of Public Health, University of Copenhagen, Copenhagen, Denmark
6. University Hospitals Centre for Health Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark