[1] Dept Publ Hlth Epidemiol & Hlth Econ, Liege, Belgium
[2] Univ Paris 07, UFR Med, Hosp Lariboisiere, AP HP,Federat Rhumatol, Paris, France
[3] Univ Queensland, Brisbane, Qld, Australia
[4] Univ Laval, Fac Med, Dept Med, Ctr Rech,CHU Quebec, Quebec City, PQ G1K 7P4, Canada
[5] CHU Quebec, Div Rheumatol, Quebec City, PQ, Canada
[6] Univ Lyon, Hosp E Herriot, INSERM, UMR 1033, Lyon, France
[7] Univ Paris 12, Hop Henri Mondor, Dept Rheumatol, UPEC, F-94010 Creteil, France
[8] Krakowskie Ctr, Krakow, Poland
[9] Catholic Univ Louvain, St Luc Univ Hosp, B-1200 Brussels, Belgium
[10] Univ Sydney, Inst Bone & Joint Res, St Leonards, NSW 2065, Australia
[11] Royal N Shore Hosp, Dept Rheumatol, St Leonards, NSW 2065, Australia
[12] Inst Rheumatol, Prague 12850, Czech Republic
[13] DIMED, Dept Med, Rheumatol Unit, Padua, Italy
[14] Univ Southampton, Lifecourse Epidemiol Unit, MRC, Southampton, Hants, England
[15] Univ Liege, Dept Publ Hlth Epidemiol & Hlth Econ, Liege, Belgium