Predicting diagnostic outcome in adult autism spectrum disorder using the autism diagnostic observation schedule, second edition

BACKGROUND: The Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) module four assessment for diagnosing autism spectrum disorder in adults has shown good sensitivity and specificity in research settings. METHOD: This study aimed to evaluate the predictive accuracy of the ADOS-2 module four by investigating the components of the assessment, in relation to diagnostic outcome in a clinical setting. Data from 88 service users referred to a Specialist Adult Autism Service was explored. RESULTS: ADOS-2 scores failed to predict the diagnostic outcome (overall sensitivity = 92%, specificity = 57%). Interestingly, scores from the ‘restricted interests’ component of the ADOS-2 have the potential to predict diagnostic outcome, despite this domain not been included in the scoring algorithm. CONCLUSIONS: Based on our findings, we recommend clinicians are cautious when interpreting results of the ADOS-2 assessment.