[1] Aarhus Univ Hosp, Dept Rheumatol, Palle Juul Jensens Blvd 99, DK-8240 Aarhus N, Denmark
[2] Aarhus Univ, Dept Clin Med, Aarhus, Denmark
[3] Higher Sch Nursing Coimbra, Hlth Sci Res Unit Nursing, Coimbra, Portugal
[4] Ctr Hosp & Univ Coimbra EPE, Rheumatol, Coimbra, Portugal
[5] Kings Coll London, Ctr Rheumat Dis, London, England
[6] Mayo Clin, Dept Qualitat Hlth Sci, Rochester, MN USA
[7] Mayo Clin, Div Rheumatol, Dept Internal Med, Rochester, MN USA