Abstract
Adult referrals to specialist autism spectrum disorder diagnostic services have increased in recent years, placing strain on existing services. It was proposed that the Ritvo Autism Asperger's Diagnostic Scale could be used as a screening tool, in order to identify and prioritise patients most likely to receive an ASD diagnosis. This study evaluates the validity of the RAADS-R as a screening tool for ASD in an adult population. Retrospective case note analysis was used to evaluate the efficacy of the RAADS-R as a screening tool to predict ASD diagnostic outcomes in 50 service users of a NHS specialist autism service. Results indicate no association between RAADS-R scores and clinical diagnostic outcome, suggesting the RAADS-R is not an effective screening tool for identifying service users most likely to receive an ASD diagnosis. In conclusion, used as a self-report measure pre-full diagnostic assessment, the RAADS-R lacks predictive validity and is not a suitable screening tool for adults awaiting autism assessments. Future research should aim to identify reliable screening tools for this purpose.