1. Copenhagen University Hospital, Bispebjerg og Frederiksberg; The Parker Institute; Frederiksberg Denmark DK-2000
2. University of Southern Denmark,; SEARCH (Research group for synthesis of evidence and research), Research Unit for Musculoskeletal Function and Physiotherapy, Institute of Sports Science and Clinical Biomechanics; Campusvej 55 Odense M Denmark 5230
3. Copenhagen University Hospital, Bispebjerg og Frederiksberg; Musculoskeletal Statistics Unit, The Parker Institute; Nordre Fasanvej 57 Copenhagen Denmark DK-2000
4. Diakonhjemmet Hospital; National Advisory Unit for Rehabilitation in Rheumatology; PO Box 23 Vindern Oslo Norway 0319
5. Frederiksberg Hospital; The Parker Institute; Frederiksberg Denmark DK-2000
6. University of Southern Denmark; SEARCH (Research group for synthesis of evidence and research), Research Unit for Musculoskeletal Function and Physiotherapy, Institute of Sports Science and Clinical Biomechanics; Campusvej 55 Odense M Denmark DK-5230
7. Bergen University College; Center for Evidence-Based Practice; Møllendalsveien 6 Bergen Norway N-5009