Purpose/Background: The increasing prevalence of Autism Spectrum Disorders (ASD) has generated increased interest in identifying children with ASD at a young age. There is much discussion in the literature regarding best practices for screening and early identification. Some argue that at a young age, a general developmental screening tool at a first level (and then autism specific screening if the child fails) is as effective as using an ASD-specific tool at selected intervals to screen all young children.
Objective: Determine the utility of using a general developmental screening tool compared to an autism specific tool when screening for ASD.
Methods: An ongoing study to improve Developmental Delay (DD) and ASD screening practices in an urban pediatric primary care practice is underway. Data has been collected on the use and results of a standardized general developmental screening tool, the PEDS® (Parents’ Evaluation of Developmental Status) and an autism-specific screening tool, the Modified Checklist for Autism in Toddlers (M-CHAT) in children ages 15 to 30 months. Assessments are complete for 66 children (55% male, mean age 23 months, 41% African American, 30% Caucasian, 15% Biracial, 14% Asian). The sensitivity, specificity, and positive predictive value of the PEDS® compared to the M-CHAT in identifying young children at risk for ASD was computed. While the sensitivity of the PEDS® compared to the M-CHAT was 77.8%, the specificity was only 26.3% and the positive predictive value was just 14.3%.
Results: Preliminary analysis indicates that in this urban pediatric population the PEDS® as a first line screen is not a good substitute for the MCHAT when screening for ASD, as children who screen negative for general developmental concerns may score positive on the M-CHAT.
Conclusions: Specific red flag items for autism, included in ASDspecific screening tools, may not be adequately examined in a this specific general developmental screening tool. These findings should be replicated in a larger population with greater ethnic diversity. Sponsor: Centers for Disease Control and Prevention.
Comment from Dr. Glascoe: The results of both papers show that the majority of children who fail the M-CHAT also receive moderate or at-risk scores on PEDS®. But problematic PEDS® results alone do little to identify which children need referrals to autism specialists, because PEDS®, like any other quality broad-band screening tool is also designed to identify other problems such as language impairment, learning disabilities, and mental retardation.
In my paper, patterns of concerns helped identify which children were likely to need referring to an autism specialist (and the latest print run of the PEDS® Brief Guide includes this information and guidance). That said, it is clear from both papers that we can do better at early detection of autism spectrum disorders if we routinely use a measure like the M-CHAT. Indeed, the American Academy of Pediatrics is now recommending administration of an ASD screen at 18 and 14 months. Although this is wise, it is critical for those involved in early detection to note that measures like the M-CHAT do not identify with much regularity, the more common disabilities of childhood. So both a broad-band screen and an ASD specific one should be deployed at these an other visits, and otherwise, an ASD screen should be administered whenever PEDS® results fall into moderate to high risk categories.