[1] Maastricht Univ, Dept Internal Med, Div Rheumatol, Med Ctr, Postbus 5800, NL-6202 AZ Maastricht, Netherlands
[2] Maastricht Univ, Care & Publ Hlth Res Inst CAPHRI, Maastricht, Netherlands
[3] Univ Padua, Dept Med DIMED, Rheumatol Unit, Padua, Italy
[4] Leiden Univ, Dept Rheumatol, Med Ctr, Leiden, Netherlands
[5] Univ Nova Lisboa, NOVA Med Sch, Lisbon, Portugal
[6] Univ Sheffield, Sch Hlth & Related Res, Hlth Econ & Decis Sci, Sheffield, S Yorkshire, England
[7] Ruhr Univ Bochum, Rheumazentrum Ruhrgebiet, Herne, Germany
[8] Univ Amsterdam, Dept Clin Immunol & Rheumatol, Med Ctr, Amsterdam, Netherlands
[9] Zuyderland Med Ctr Heerlen, Dept Rheumatol, Heerlen, Netherlands
[10] Kings Coll Hosp London, Dept Rheumatol, London, England
[11] Kings Coll London, Ctr Rheumat Dis, London, England