1. Institute of Health Sciences, Kristiania University College, Oslo, Norway
2. Warwick Clinical Trials Unit, Warwick Medical School, University of Warwick, Coventry, UK
3. Centre for Applied Research in Health, School of Human & Health Sciences, University of Huddersfield, Huddersfield, UK
4. Faculty of Health Sciences, School of Physical Therapy, Western's Bone and Joint Institute, University of Western Ontario, London, Canada
5. Primary Care Centre Versus Arthritis, School of Primary, Community and Social Care, Faculty of Medicine and Health Sciences, Keele University, Staffordshire, UK
6. Division of Physical Medicine and Rehabilitation, Vestfold Hospital Trust, Tønsberg, Norway
7. NORCE Norwegian Research Centre, Bergen, Norway
8. Department of Psychology, Royal Holloway, University of London, Egham, UK
9. Department of Rehabilitation, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
10. Department of Rehabilitation Medicine, Research School CAPHRI, Maastricht University, Maastricht, the Netherlands, and CIR Revalidatie, Eindhoven, the Netherlands;
11. University Hospitals of Coventry and Warwickshire, Coventry, UK