[1] Diakonhjemmet Hosp, Div Rheumatol & Res, Oslo, Norway
[2] Boston Univ, Sch Med, Rheumatol Sect, Boston, MA USA
[3] Univ Oslo, Dept Interdisciplinary Hlth Sci, Oslo, Norway
[4] Univ Oslo, Dept Orthopaed, Oslo, Norway
[5] Diakonhjemmet Sykehus, Alderspsykiatrisk Avdeling, Oslo, Norway
[6] Univ Oslo, Fac Med, Oslo, Norway
[7] Norwegian Ctr Ageing & Hlth, Oslo, Norway
[8] Univ Oslo, Dept Geriatr Med, Oslo, Norway
[9] Univ Oslo, Div Orthopaed Surg, Oslo, Norway
[10] Lund Univ, Dept Clin Sci, Lund, Sweden