Measuring Anxiety in Autistic Children: Assessing the Validity of the Anxiety Scale for Children with Autism Spectrum Disorder

The present study assessed the validity of one of the first autism-specific anxiety measures, the Anxiety Scale for Children with Autism Spectrum Disorder (ASC-ASD), and compared its ability to predict parent-reported clinical anxiety to a 'traditional' anxiety measure, the Spence Children's Anxiety Scale (SCAS). Whether the inclusion of the child form for each measure improved the predictive ability of the parent forms was also examined. Eighty-seven parents of autistic children, aged 8-12 years, completed the ASC-ASD, the SCAS, and the Social Communication Questionnaire (SCQ), a screener for autism characteristics. Of these parents, 56 had their child complete the ASC-ASD and SCAS. The children with a reported anxiety diagnosis were rated significantly higher by their parents on both the SCAS and the ASC-ASD compared to the non-anxious children. Pearson's correlation coefficients indicated that the ASC-ASD had good divergent and convergent validity, as demonstrated by a poor, non-significant correlation with the SCQ and a strong, significant correlation with the SCAS. Regression analyses indicated that while the ASC-ASD was a significant predictor of parent-reported clinical anxiety in autistic children, the SCAS was not. Neither model was improved with the inclusion of the respective child form. This study is the first to demonstrate the ability of the ASC-ASD to predict child clinical anxiety disorder status and adds to the growing body of evidence for the validity of this measure. The findings also suggest that parent reports of anxiety may be sufficient to identify autistic children warranting further clinical investigation of anxiety in this age group.