Objectives: To evaluate the utility of two screening measures for ASD in young children in a tertiary care clinic setting, including:
- utility in a clinic-referred sample of children at risk for developmental disabilities
- identification of children without a referral question of ASD who were in need of ASD-specific evaluation
- utility in a more expanded age range (up to 48 months)
- how each measure individually and together predicted ASD diagnosis.
Methods: As part of the intake process for referred children under the age of 4 years, caregivers completed the CSBS-ITC and M-CHAT in addition to a general intake form requesting information about development and referral question. Screeners are used by clinic staff to inform assessment procedures, including whether the child will receive an ASD-specific evaluation in addition to other interdisciplinary assessments. Based on referral question and/or scores on screeners, children were routed to either ASD-specific or more general developmental evaluations. Final diagnoses utilized ADI-R/ADOS and were concluded by members of the interdisciplinary team.
Results: 138 children have been screened using these procedures; diagnostic assessments have been completed on a subset (n = 29). Within the available data, 69% of the children who had a question of ASD were confirmed to have an ASD diagnosis. Among the children with confirmed ASD, 85% were detected with the M-CHAT and 92% were detected with the CSBS-ITC. Within this sample, the positive predictive values for the M-CHAT and CSBS-ITC were 58% and 50%, respectively. Negative predictive values were 80% for the M-CHAT and 75% for the CSBS-ITC. Of the children who screened positive on one or both of the screeners but did not have a referral question of ASD, none received an ASD diagnosis upon specific evaluation. Evaluations are in progress or will be scheduled for an additional 60 children.
Conclusions: Preliminary data indicates that children at-risk for ASD are already being referred for an ASD-specific evaluation. The positive predictive values are lower in the current sample than has been previously reported in community-based samples, warranting additional analyses. The rates of false positives observed on the CSBS-ITC in this sample is likely related to the nature of the non-ASD referrals to our clinics, as most children referred in this age range have concerns regarding language and/or other developmental delays. Subsequent analyses will explore the utility of these measures both within and beyond the typical age ranges for these measures.