Assessing Toddlers and Preschool Children Using the Checklist for Autism Spectrum Disorder

Brief, clinically feasible instruments are needed to assess autism spectrum disorder (ASD) in toddlers and preschoolers so that children can access early evidence-based intervention. Study purposes were to (1) compare scores on the 30-item Checklist for Autism Spectrum Disorder (CASD) and 6-item CASD-Short Form (CASD-SF) for toddlers and preschoolers and older children with ASD to determine whether scores differed by age and (2) establish sensitivity and specificity for the CASD and CASD-SF for toddlers and preschoolers. Samples were 1,266 children with ASD 1–17 years of age, 97 toddlers and preschoolers with diagnoses other than ASD, and 65 typical toddlers and preschoolers. CASD and CASD-SF scores were somewhat higher for toddlers and preschoolers than for older children with ASD, indicating that young children were not at increased risk for being missed. All toddlers and preschoolers with ASD had CASD scores in the autism range, and 99.7% had CASD-SF scores in the autism range. CASD and CASD-SF scores correctly identified 100% and 96.9% of typical toddlers and preschoolers and 100% and 96.2% of toddlers and preschoolers with disorders other than ASD, respectively, as not having ASD. Results demonstrate high CASD and CASD-SF sensitivity and specificity for toddlers and preschoolers.