Systematic reviews have traditionally focused on internal validity, while external validity often has been overlooked. In this study, we systematically reviewed determinants of external validity in the accumulated randomized controlled trials of social skills group interventions for children and adolescents with autism spectrum disorder. We…

To determine maternal stress and child variables predicting maternal stress, 104 mothers of children with autism spectrum disorder (ASD) and intellectual disability (ID) completed the Dutch version of the Parental Stress Index (PSI; De Brock, Vermulst, Gerris, & Abidin, 1992) every six months over a period of two years. The level of maternal…

The present study examines the validity of the Dutch Children's Communication Checklist (CCC) for children in kindergarten in a community sample, in order to assess the feasibility of using it as a screening instrument in the general population. Teachers completed the CCC for a representative sample of 1396 children at kindergarten level, taken…

Analysis of parent and teacher Developmental Behavior Checklist (DBC) ratings on a combined sample of 1,536 Dutch and Australian children (ages 3-22) with mild to profound intellectual disabilities produced five subscales: Disruptive/Antisocial, Self-Absorbed, Communication Disturbance, Anxiety, and Social Relating. Internal consistency of the…