[1] McGill Univ, Div Clin Epidemiol, Ctr Hlth, Montreal, PQ, Canada
[2] Toronto Western Hosp, Dept Rheumatol, Toronto, ON M5T 2S8, Canada
[3] CHU Quebec, Div Rheumatol, Quebec City, PQ, Canada
[4] Univ Laval, Quebec City, PQ, Canada
[5] Univ Manitoba, Dept Rheumatol, Winnipeg, MB, Canada
[6] Northwestern Univ, Feinberg Sch Med, Dept Med Rheumatol, Chicago, IL 60611 USA
[7] Johns Hopkins Univ, Sch Med, Div Rheumatol, Baltimore, MD USA
[8] West Penn Allegheny Hlth Syst, Dept Med, Pittsburgh, PA USA
[9] Suny Downstate Med Ctr, Div Rheumatol, Brooklyn, NY 11203 USA
[10] Univ Calif San Francisco, Div Rheumatol, San Francisco, CA USA
[11] Univ Calif San Francisco, Dept Med, Rosalind Russell Med Res Ctr Arthrit, San Francisco, CA USA
[12] Univ Calif Los Angeles, David Geffen Sch Med, Cedars Sinai Med Ctr, Los Angeles, CA 90095 USA
[13] Univ N Carolina, Dept Rheumatol, Chapel Hill, NC USA
[14] Univ Alabama Birmingham, Dept Rheumatol, Birmingham, AL USA
[15] Hanyang Univ, Hosp Rheumat Dis, Seoul 133791, South Korea
[16] Univ Lund Hosp, Dept Rheumatol, S-22185 Lund, Sweden
[17] Rigshosp, Dept Rheumatol, DK-2100 Copenhagen, Denmark
[18] Copenhagen Univ Hosp, Gentofte Hosp, Copenhagen, Denmark