[1] Manchester Acad Hlth Sci Ctr, Northern Care Alliance NHS Fdn Trust, Manchester, England
[2] Salford Royal Hosp, Rheumatol Dept, Salford, England
[3] Univ Manchester, Fac Biol Med & Hlth, Div Musculoskeletal & Dermatol Sci, Manchester, England
[4] Salford Royal Hosp, Rheumatol Dept, Stott Lane, Salford M6 8HD, England