[1] Radboud Univ Nijmegen Med Ctr, Dept Primary & Community Care, Intellectual Disabil & Hlth, Radboud Inst Hlth Sci, Nijmegen, Netherlands
[2] Radboud Univ Nijmegen Med Ctr, Dept Primary & Community Care, Radboud Inst Hlth Sci, POB 9101,Route 149, NL-6500 HB Nijmegen, Netherlands
[3] Erasmus MC, Univ Med Ctr, Dept Gen Practice, Intellectual Disabil Med, Rotterdam, Netherlands
[4] Univ Nevada, Dept Phys Therapy, Las Vegas, NV 89154 USA