1. Centre of Head and Orthopaedics, Rigshospitalet; Copenhagen Center for Arthritis Research, Department of Rheumatology and Spine Diseases; Glostrup Denmark
2. University of Copenhagen; Department of Clinical Medicine; Copenhagen Denmark
3. Diakonhjemmet Hospital; Preventive Cardio-Rheuma Clinic; Oslo Norway
4. Bispebjerg and Frederiksberg Hospital; Musculoskeletal Statistics Unit, The Parker Institute; Copenhagen Denmark
5. Odense University Hospital; Department of Rheumatology; Odense Denmark
6. Copenhagen University Hospital Herlev-Gentofte; Herlev Anaesthesia Critical and Emergency Care Science Unit (ACES), Department of Anesthesiology; Copenhagen Denmark