The 40 item Social Communication Questionnaire (SCQ) screens for autism spectrum disorder (ASD) and is quicker to administer than the (two hour) Autism Diagnostic Interview-Revised (ADI-R). A recent study, however, found that two questions on the SCQ were answered “autism positive” in 40% of a normal population children's sample. A modified SCQ (MSCQ) without these questions may be more specific than the SCQ.

To compare the performance of the MSCQ with that of the ADI-R.

42 children were recruited to the study, 22 from Mater CAMHS and 20 from St Paul's Hospital and Special School. 20 were diagnosed with autism, 10 with ASD, and 12 with other clinical diagnoses. The MSCQ was sent out as a postal questionnaire to be completed before attending for ADI-R interview. To assess the diagnostic validity of the MSCQ correlations between the MSCQ and ADI-R were calculated. Receiver operating characteristic (ROC) curves were then applied to assess its discriminate ability.

A strong correlation of 0.84 was found between ADI-RTotal and MSCQTotal scores. Using ROC Curves, a cut-off of 14.5 on the MSCQ had a sensitivity of 0.90 and a specificity of 0.82 for identifying ASD from other clinical disorders. A cut-off of 21.5 on the MSCQ had a sensitivity of 0.75 and a specificity of 0.77 for identifying autism from other diagnoses.

These preliminary findings suggest that the MSCQ is a clinically useful and accurate method of assessing for ASD.