[1] Univ Cambridge, Inst Publ Hlth, Cambridge, England
[2] City Hosp, Dept Rheumatol, St Albans, Herts, England
[3] St Georges Healthcare NHS Trust, Dept Rheumatol, London, England
[4] Sherwood Forest Hosp NHS Fdn Trust, Dept Rheumatol, Nottingham, England
[5] Hereford Hosp NHS Trust, Dept Rheumatol, Hereford, England