[1] Univ Sheffield, Sch Hlth & Related Res, Hlth Technol Assessment, Sheffield, S Yorkshire, England
[2] Univ Sheffield, Sch Hlth & Related Res, Hlth Econ, Sheffield, S Yorkshire, England
[3] Univ Sheffield, Sch Hlth & Related Res, Econometr, Sheffield, S Yorkshire, England
[4] Univ Sheffield, Sch Hlth & Related Res, Decis Sci, Sheffield, S Yorkshire, England
[5] Univ Sheffield, Sch Hlth & Related Res, Sheffield, S Yorkshire, England
[6] Kings Coll Hosp NHS Fdn Trust, Dept Rheumatol, Clin Rheumatol, London, England
[7] Univ Hertfordshire, Clin Rheumatol, Ctr Lifespan & Chron Illness Res, Hatfield AL10 9AB, Herts, England