To characterize children presenting with concerns for autism spectrum disorder (ASD) missed by parent-report screeners and to examine benefits of a combined screening approach with the Modified Checklist for Autism in Toddlers, Revised (M-CHAT-R) and the Ages and Stages Questionnaire, Third Edition (ASQ-3).
Participants included were 154 children aged 16 to 42 months presenting for an evaluation at an autism center. Caregivers completed the M-CHAT-R, ASQ-3, and a demographic questionnaire. Children participated in an autism diagnostic evaluation consisting of the Mullen Scales of Early Learning (Mullen) and Autism Diagnostic Observation Schedule, Second Edition (ADOS-2).
A total of 124 children (81%) were diagnosed with ASD. The M-CHAT-R identified 85% (n = 105) of these children. Children with ASD missed by the M-CHAT-R had significantly higher scores on the Mullen and significantly lower scores on the ADOS-2. Of the ASQ-3 domains, the majority (n = 102, 82%) of children with ASD failed the communication domain; missed cases showed similar patterns of higher Mullen scores and lower ADOS-2 scores. When adopting a combined screening approach, using a failed screen from either the M-CHAT-R or ASQ-3 communication domain, 93% of children were identified. Parent-reported concerns on an open-ended questionnaire revealed ASD red flags for many missed cases.
Children with ASD missed by screeners had higher scores on developmental testing and lower scores on the ADOS-2; however, children still performed below average on developmental tests. Our findings suggest that a combined screening approach was most effective for identifying children with ASD from a sample group referred for an ASD evaluation.