Screening for Autism Spectrum Disorders: A Re-Examination of the SCQ and SRS

Background: The current gold standard in clinical and research evaluations of Autism Spectrum Disorders (ASDs) includes the Autism Diagnostic Interview-Revised (Rutter, Le Couteur, & Lord, 2003) and the Autism Diagnostic Observation Schedule (ADOS: Lord et al., 2000). More recently, a number of screening instruments and diagnostic procedures have been introduced that include the Social Responsiveness Scale (SRS: Constantino, 2002) and the Social Communication Questionnaire (SCQ: Rutter, Bailey, & Lord, 2003). These instruments provide a large amount of information in a relatively short amount of time. However, the empirical findings on the utility of these measures have been mixed. The sensitivity and specificity of the instruments varies depending on child age and other characteristics such as language level. Given the heterogeneity of ASDs, an important next step is to examine the performance of the SRS and SCQ in specific (e.g., age by language) subsets of children with ASD. In addition, the inclusion of measures of adaptive functioning should be considered as possible way to improve the ability of the SRS and SCQ to correctly identify ASDs (see Tomanik et al., 2007).

Objectives: This study will examine the performance of the SCQ and SRS in phenotypically diverse samples of children with ASD.  

Methods: The present study utilizes previously collected data. Subjects will include approximately 2,686 individuals, ages 4 to 12 years. Diagnoses of ASD were confirmed with clinical diagnostic evaluations. Measures included the ADI-R, the ADOS, the SCQ, and the SRS. Classifications based on the SCQ and SRS will be compared with clinical diagnoses. In addition, the Vineland Adaptive Behavior Scales, 2^nd Edition (Vineland-II: Sparrow, Cicchetti, & Balla, 2005) will be used to assess whether the accuracy of the instruments improves when a measure of adaptive functioning is included. Correlational analyses will also be conducted to examine the validity of the SCQ and SRS as measures of ASD severity relative to the new ADOS severity metric.

Results: Results of the data analyses described above will be presented. Implications for research and clinical practice will be discussed.
Conclusions: By using a large and phenotypically diverse sample, the results from this study will add to our existing knowledge of the SCQ and SRS and advance research on the identification of ASDs.