[1] Ruhr Univ Bochum, Rheumazentrum Ruhrgebiet Herne, Bochum, Germany
[2] Leiden Univ, Dept Rheumatol, Med Ctr, Leiden, Netherlands
[3] Zuyderland Med Ctr, Heerlen, Netherlands
[4] Univ Alberta, Dept Med, Edmonton, AB, Canada
[5] Univ Copenhagen, Dept Clin Med, Copenhagen, Denmark
[6] Rigshosp, Copenhagen Ctr Arthrit Res, Ctr Rheumatol, Glostrup, Denmark
[7] UCB Pharma, Monheim, Germany
[8] UCB Pharma, Brussels, Belgium
[9] UCB Pharma, Slough, Berks, England
[10] Charite Univ Med Berlin, Dept Gastroenterol Infect Dis & Rheumatol, Berlin, Germany
[11] German Rheumatism Res Ctr, Dept Epidemiol, Berlin, Germany