[1] Katholieke Univ Leuven, Fak Kinesiol & Rehabil Sci, Dept Rehabil Sci, B-3001 Louvain, Belgium
[2] Vrije Univ Brussels, Fac Med & Pharm, Dept Med Sociol & Hlth Sci, Brussels, Belgium
[3] City Hosp NHS Trust, Dept Rehabil Sci, Nottingham, England
[4] Univ Hosp Pellenberg, Pellenberg, Belgium
[5] Katholieke Univ Leuven, Ctr Biostat, B-3000 Louvain, Belgium
[6] Univ Nottingham, Inst Work Hlth & Org, Nottingham NG7 2RD, England