Our objective was to determine if the Checklist for Autism Spectrum Disorder (CASD) was inadvertently overemphasizing autism symptoms in a population of children without autism.
Children noted with communication delays were referred to both a developmental pediatrician and a speech and language pathologist for an apraxia and autism evaluation. All children who underwent both autism and apraxia evaluations and met rule-in or rule-out criteria for both diagnoses were included in the study, resulting in a sample size of 30.
Our results show that 63.6% of children initially diagnosed with autism also had apraxia, 36.8% of children initially diagnosed with apraxia also had autism, 23.3% had neither, and 23.3% had both. Overall diagnostic accuracy for the CASD was 96.7%. Overall accuracy for the CASD for children without apraxia was 100% and accuracy for children with apraxia was 94.7%. Specificity for the CASD was 100%, while sensitivity was 90.9%. The PPV was 100% and the NPV was 95.0%.
This study demonstrates that the CASD does not overemphasize autism symptoms in a population of children without autism. It also shows that autism and apraxia are highly comorbid. Thus, it is important to monitor all children diagnosed with apraxia for signs of autism and all children diagnosed with autism for signs of apraxia. This will help identify children as early as possible and allow them access to services appropriate to their needs.