Background: This study is the first to evaluate the Social Communication Questionnaire (SCQ) and the Developmental Behaviour Checklist-Autism Screening Algorithm (DBC-ASA) in the same sample of school-aged children with intellectual disability (ID) with and without Pervasive Developmental Disorders (PDDs).
Method: Parents of 49 children (36 with PDDs and 13 with ID) completed a survey that included a demographic form, a measure of adaptive behaviour (the SIB-R), the SCQ, and the DBC-ASA.
Results: According to established cut-offs, the SCQ's sensitivity was .92 and specificity was .62, and the DBC-ASA's sensitivity was .94 and specificity was .46. Six of the seven false positives on the DBC-ASA had DBC Total Problem Behaviour scores above the clinical cut-off. By contrast, all six true negatives had Total Problem Behaviour scores below the clinical cut-off. No such pattern was noted for the SCQ.
Conclusion: While both instruments have good psychometric properties, the results of this study suggest that clinicians and researchers should exercise caution when utilising the DBC-ASA to screen for PDDs in individuals with significant behaviour problems, as this could decrease its diagnostic validity.