[1] Univ Munich, Dept Phys Med & Rehabil, DE-81377 Munich, Germany
[2] Univ Munich, IMBK, WHO FIC Collaborating Ctr DIMDI, ICF Res Branch, Munich, Germany
[3] Univ Melbourne, Victorian Rehabil Res Inst, Melbourne, Vic, Australia
[4] Royal Melbourne Hosp, Melbourne, Vic, Australia
[5] Univ Freiburg, Dept Qual Management & Social Med, D-7800 Freiburg, Germany
[6] Univ Hosp, Dept Internal Med, Div Rheumatol, Maastricht, Netherlands
[7] WHO, Classificat Assessment Surveys & Terminol Team, CH-1211 Geneva, Switzerland
[8] Maastricht Univ, Dept Epidemiol, Maastricht, Netherlands