The Pediatric Autism Spectrum Therapy Observation System: Development, Psychometric Properties, and Sensitivity to Treatment.

An observational coding system was developed to track clinical change in children with autism spectrum disorder (ASD) during psychotherapy. The Pediatric Autism Spectrum Therapy Observation System (PASTOS) consists of 23 items divided into 5 subscales and is used to rate child behaviors in individual psychotherapy sessions. Manual-based cognitive behavioral therapy session transcripts of 22 children diagnosed with ASD (IQ > 70) and a concurrent anxiety disorder (M = 9.41 years, SD = 1.56 years) enrolled in a randomized, controlled trial were coded. Results suggested that the PASTOS exhibited promising interrater reliability, internal consistency, convergent validity at post-treatment, and treatment sensitivity. The PASTOS may be a useful tool for studying process and outcome in psychotherapy research on children with ASD.