1. Parental and Special Education Research Unit, Faculty of Psychology and Educational Sciences and Faculty Clinical Centre PraxisP, University of Leuven , Leuven 3000, Belgium
2. S:PAM (Studies in Performing Arts & Media), Faculty of Arts and Philosophy, Ghent University , Ghent 9000, Belgium
3. Section for Health Services Research, Department of Public Health, University of Copenhagen , 1353 Copenhagen K, Denmark