[1] Leiden Univ, Med Ctr, Dept Rheumatol, NL-2300 RC Leiden, Netherlands
[2] Med Univ Vienna, Dept Internal Med 3, Vienna, Austria
[3] Hietzing Hosp, Ctr Rheumat Dis, Dept Med 2, Vienna, Austria
[4] Amsterdam Rheumatol Ctr, Amsterdam, Netherlands
[5] Atrium Med Ctr Heerlen, Dept Rheumatol, Heerlen, Netherlands
[6] Univ Cattolica Sacro Cuore, Sch Med, Inst Rheumatol & Affine Sci, Div Rheumatol, I-00168 Rome, Italy
[7] Univ Coimbra, Hosp & Fac Med, Dept Rheumatol, P-3000 Coimbra, Portugal
[8] Univ Liverpool, Inst Chron Dis & Ageing, Liverpool L69 3BX, Merseyside, England
[9] UMass Mem Med Ctr, Div Rheumatol, Dept Med, Worcester, MA USA
[10] Univ Massachusetts, Sch Med, Worcester, MA USA