[1] Radboud Univ Nijmegen, Radboud Inst Hlth Sci, Dept Primary & Community Care, Res Grp Intellectual Disabil & Hlth,Med Ctr, POB 9101, NL-6500 HB Nijmegen, Netherlands
[2] Univ Med Ctr Rotterdam, Dept Gen Practice, Erasmus MC, Intellectual Disabil Med, POB 2040, NL-3000 CA Rotterdam, Netherlands
[3] Wageningen Univ, Dept Social Sci Hlth & Soc, POB 8130, NL-6706 KN Wageningen, Netherlands
[4] Radboud Univ Nijmegen, Radboud Inst Hlth Sci, Dept Primary & Community Care, Med Ctr, POB 9101, NL-6500 HB Nijmegen, Netherlands