1. Isle of Wight NHS Trust, St Mary's Hospital, Parkhurst Road, Newport, Isle of Wight, PO30 5TG, UK
2. Dartford and Gravesham NHS Trust, Darent Valley Hospital, Darenth Wood Road, Dartford, DA2 8DA, UK
3. Nuffield Department of Orthopaedics Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, OX3 7HE, UK
4. National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074
5. Centre for Pain IMPACT, Neuroscience Research Australia, Sydney, 2031, Australia
6. School of Health Sciences, University of New South Wales, Sydney, 2052, Australia
7. Centre for Statistics in Medicine, Nuffield Department of Orthopaedics Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, OX3 7HE, UK
8. Centre for Evidence-Based Medicine, Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford, OX2 6GG, UK
9. School of Allied Health, University of Limerick, Ireland
10. Health Research Institute, University of Limerick, Ireland