Toddler Autism Symptom Inventory (TASI): Use in Diagnostic Evaluations of Toddlers

Although symptoms of autism are present early in life and early diagnosis can lead to better outcomes, there is a lack of validated parent interviews for children under the age of three. We developed the Toddler Autism Symptom Inventory (TASI), an interview form designed to assess the presence and absence of skills and symptoms in children aged 12-36 months. Reliability of symptoms and diagnosis, and validity of algorithms designed in accordance with Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) and International Classification of Diseases, Tenth Revision (ICD-10) diagnostic criteria were established. Reliability and validity of four algorithms were found to be good (n = 204). A validation sample (n = 91) confirmed these findings, and algorithms showed no reduction in validity in two subsamples of children: those under age 24 months and those with a developmental age below 18 months.