Autism spectrum disorders in children with physical or mental disability or both. II: Screening aspects.

The Autism Behavior Checklist (ABC) was used as a screening instrument in a study of autism spectrum disorders in a population of children with mental retardation or physical disability or both. The ABC score clearly reflected behavioural problems found in children with mental retardation and not only behaviours typical of autism. If the cut-off score used was 45 (lower than recommended by the original investigators), children with autistic disorder without multiple other disabilities were reliably identified, with an acceptable rate of false positive cases. In order not to miss other autism spectrum disorders, all cases with several omitted items in their checklists were examined in more detail. The Childhood Autism Rating Scale (CARS) distinguished reasonably well between autistic disorder and other autism spectrum disorders.