[1] Med Univ Vienna, Div Rheumatol, A-1090 Vienna, Austria
[2] Univ Hosp Maastricht, Maastricht, Netherlands
[3] Johns Hopkins Univ, Baltimore, MD USA
[4] Vrije Univ Amsterdam, Med Ctr, Amsterdam, Netherlands
[5] Inst Work & Hlth, Toronto, ON, Canada
[6] Univ Pisa, Pisa, Italy
[7] Univ British Columbia, Vancouver, BC V5Z 1M9, Canada
[8] CHU Montpellier, Montpellier, France
[9] Paris Descartes Univ, Paris, France
[10] Univ Leeds, Leeds, W Yorkshire, England
[11] Univ Santiago de Compostela, Sch Med, Santiago, Spain
[12] Univ Toronto, Toronto, ON, Canada
[13] Univ N Carolina, Chapel Hill, NC USA
[14] Diakonhjemmet Hosp, Oslo, Norway
[15] Hosp Univ La Paz, Madrid, Spain
[16] Univ Florence, Florence, Italy
[17] Univ Nebraska, Omaha, NE 68182 USA
[18] Univ Calif Los Angeles, Los Angeles, CA USA
[19] NYU, Hosp Joint Dis, New York, NY USA
[20] Univ Bristol, Bristol, Avon, England
[21] Beth Israel Deaconess Med Ctr, Boston, MA 02215 USA
[22] US FDA, Rockville, MD 20857 USA
[23] Med Univ Vienna, Vienna, Austria
[24] Hietzing Hosp, Vienna, Austria
[25] Jyvaskyla Cent Hosp, Jyvaskyla, Finland
[26] Stanford Univ, Portola Valley, CA USA
[27] Inst Populat Hlth, Ottawa, ON, Canada
[28] Leiden Univ, Med Ctr, Leiden, Netherlands
[29] Radboud Univ Nijmegen, Med Ctr, NL-6525 ED Nijmegen, Netherlands
[30] Boston Univ, Sch Med, Boston, MA 02118 USA
[31] Karolinska Univ Hosp, Stockholm, Sweden
[32] NIH, Bethesda, MD 20892 USA
[33] Brigham & Womens Hosp, Boston, MA 02115 USA
[34] Univ Ottawa, Ottawa, ON, Canada
[35] Medimmune Inc, Gaithersburg, MD 20878 USA
[36] Natl Data Bank Rheumat Dis, Wichita, KS USA
[37] Charite, Berlin, Germany