[1] Univ Oxford, Botnar Res Ctr, Nuffield Dept Orthopaed Rheumatol & Musculoskelet, Oxford OX3 7LD, England
[2] Univ Messina, Rheumatol Unit, Dept Clin & Expt Med, I-98122 Messina, Italy
[3] Univ Autonoma Madrid, Rheumatol Unit, Hosp Univ La Paz, La Paz Inst Hlth Res IdiPAZ, Paseo de la Castellana 261, Madrid 28046, Spain
[4] Sorbonne Univ, Inst Pierre Louis Epidemiol & Sante Publ, F-75006 Paris, France
[5] Sorbonne Univ, Dept Rheumatol, Pitie Salpetriere Hosp, AP HP, F-75013 Paris, France
[6] Justus Liebig Univ Giessen, Dept Rheumatol & Clin Immunol, Campus Kerckhoff, D-61231 Bad Nauheim, Germany
[7] Univ Western Ontario, St Josephs Hlth Care, Schulich Sch Med, London, ON N6A 5C1, Canada