[1] Amsterdam Rehabil Res Ctr Reade, Amsterdam, Netherlands
[2] Vrije Univ Amsterdam, Med Ctr, EMGO Inst Hlth & Care Res, Dept Rehabil Med, Amsterdam, Netherlands
[3] Slotervaart Hosp, Dept Orthoped, Amsterdam, Netherlands
[4] Univ Jyvaskyla, Dept Hlth Sci, Jyvaskyla, Finland
[5] Jyvaskyla Cent Hosp, Jyvaskyla, Finland
[6] Vrije Univ Amsterdam, Med Ctr, Dept Epidemiol & Biostat, EMGO Inst Hlth & Care Res, Amsterdam, Netherlands
[7] Vrije Univ Amsterdam, Med Ctr, Dept Rheumatol, Amsterdam, Netherlands