[1] Geneva Univ Hosp, Dept Rheumatol, Geneva, Switzerland
[2] Univ Michigan, Div Rheumatol, Ann Arbor, MI 48109 USA
[3] Swiss Clin Qual Management Fdn, Zurich, Switzerland
[4] Univ Hosp Zurich, Dept Rheumatol, Zurich, Switzerland
[5] OsteoRheuma Bern, Bern, Switzerland
[6] Univ Munster, Inst Epidemiol & Social Med, Munster, Nordrhein Westf, Germany
[7] Univ Hosp Basel, Dept Rheumatol, Basel, Switzerland