Norms and cut off scores for the autism spectrum disorders diagnosis for adults (ASD-DA) with intellectual disability

Establishing the cut-off scores for Autism Spectrum Disorder-Diagnostic (ASD-DA) scale for adults with intellectual disability (ID) and autism or PDD-NOS was the primary goal of this investigation. The aim of Study 1 was to determine if the ASD-DA was able to differentiate between adults with ID with and without an autism spectrum disorder, and to determine a total score cut-off for this purpose. The aim of Study 2 was to determine if the ASD-DA was able to differentiate between autism and PDD-NOS in this population. Sensitivity, specificity, and receiver operating characteristics (ROC) were computed for potential cut-off scores and were found to be acceptable. The implications of these data for diagnosing ASD in adults with ID are discussed.