Expediting clinician assessment in the diagnosis of autism spectrum disorder

Aim To investigate a novel observational rating protocol designed to expedite clinical diagnosis of autism spectrum disorder (ASD). Method Two hundred and forty patients referred to a tertiary autism center (median age 8y 9mo, range 2y 6mo–34y 8mo; 188 males, 52 females) were rated using an adaptation of the Childhood Autism Rating Scale, Second Edition (CARS‐2) based exclusively on patient observation (CARS‐2obs). Scores were compared to expert diagnosis of ASD, parent‐reported Social Responsiveness Scale, Second Edition (SRS‐2) and, in a selected subset of patients, the Autism Diagnostic Observation Schedule, Second Edition (ADOS‐2). Results CARS‐2obs distinguished patients with a clinical diagnosis of ASD from those with non‐ASD neuropsychiatric disorders (mean score=18 vs 11.7, p