[1] Leiden Univ, Dept Rheumatol, Med Ctr, Leiden, Netherlands
[2] Ctr Hosp & Univ Coimbra, Dept Rheumatol, Coimbra, Portugal
[3] Univ Amsterdam, Dept Rheumatol, Med Ctr, Amsterdam, Netherlands
[4] Zuyderland Med Ctr, Dept Rheumatol, Rheumatol, Heerlen, Netherlands
[5] Diakonhjemmet Hosp, Ctr Treatment Rheumat & Musculoskeletal Dis REMED, Oslo, Norway
[6] Groene Hart Ziekenhuis, Dept Rheumatol, Gouda, Netherlands