1. University of the West of England; Faculty of Health & Life Sciences; Glenside campus Blackberry Hill Bristol UK BS16 1DD
2. University of Bristol, Bristol Royal Infirmary; Rheumatology Unit; The Courtyard Marlborough Street Bristol UK BS2 8 HW
3. Cardiff University School of Medicine; Section of Rheumatology, Department of Medicine; Bioengineering & Rheumatology Research Institute (BARRI) Building Heath Park Cardiff UK CF14 4XN
4. Institute of Psychiatry, King's College London; Department of Psychological Medicine; Weston Education Centre Cutcombe Road London UK SE5 9RH
5. Copenhagen University Hospital, Frederiksberg, Copenhagen, Denmark; Musculoskeletal Statistics Unit (MSU), The Parker Institute, Dept Rheumatology; Nordrefasanvej 57 Copenhagen Denmark DK-2000