Brief report: excluding the ADI-R behavioral domain improves diagnostic agreement in toddlers.

Past research shows poor agreement between the Autism Diagnostic Interview-Revised (ADI-R) and other diagnostic measures in toddlers. Our goal was to examine whether exclusion of the ADI-R behavioral domain results in improved diagnostic agreement. Toddlers aged 16-37 months (M = 26 months) received an evaluation because they failed the Modified Checklist for Autism in Toddlers (n = 142). Evaluations included the ADI-R, Autism Diagnostic Observation Schedule, Childhood Autism Rating Scale, and clinical judgment. Results found poor to fair agreement between the ADI-R and other measures; agreement improved when the ADI-R behavioral domain was excluded. These findings suggest that stereotyped interests and behaviors are not as relevant to the ADI-R as other diagnostic criteria when evaluating toddlers for autism spectrum disorders.