[1] Univ Med Ctr Utrecht, Dept Rheumatol & Clin Immunol, NL-3508 GA Utrecht, Netherlands
[2] Vrije Univ Amsterdam Med Ctr, Dept Clin Epidemiol & Biostat, Amsterdam, Netherlands
[3] Univ Bristol, Bristol Royal Infirm, Acad Rheumatol Unit, Bristol, Avon, England
[4] Charite, Dept Rheumatol & Clin Immunol, D-13353 Berlin, Germany
[5] EULAR Social Leagues Patients Representat, Leuven, Belgium
[6] Kings Coll London, Acad Dept Rheumatol, Sir Alfred Baring Garrod Clin Trials Unit, London WC2R 2LS, England
[7] Univ Genoa, Dept Internal Med, Res Lab, I-16126 Genoa, Italy
[8] Hosp Univ Coimbra, Coimbra, Portugal
[9] Univ Paris 05, Hop Cochin, AP HP, Serv Med Interne,Ctr Reference Natl Plan Malad Ra, Paris, France
[10] Natl Inst Rheumat Dis Piestany, Piestany, Slovakia
[11] Univ Alabama Birmingham, Div Clin Immunol & Rheumatol, Birmingham, AL 35294 USA
[12] Univ Hosp KU Leuven, Dept Rheumatol, Leuven, Belgium