1. Radboud University Nijmegen Medical Centre; Centre for Quality of Care Research (WOK); (117 KWAZO) PO Box 9101 Nijmegen Netherlands 6500 HB
2. University of Maastricht; Centre for Quality of Care Research; PO Box 616 6200 MD Maastricht Netherlands
3. Radboud University Nijmegen Medical Centre; Scientific Institute for Quality of Health Care; 114 IQ Health Care PO Box 9101 Nijmegen Netherlands 6500 HB