1. From Department of Rehabilitation Sciences (L.D.W., I.B., H.F., W.D.W.), Faculty of Kinesiology and Rehabilitation Sciences, Katholieke Universiteit Leuven, Belgium; Department of Health Sciences and Medical Sociology (K.P., M.L., F.L.), Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Belgium; RehaClinic Zurzach (B.S., F.A., C.K., W.J.), Switzerland; NHS Trust (P.B.) Nottingham, UK; Biostatistical Center (A.K., K.B., E.L.), Katholieke Universiteit Leuven, Belgium; Fachklinik...