A quarterly publication of the Autism Research Institute

The Autism Research Review International is quarterly publication of the Autism Research Institute

Fall, 2019 | Number 4, Volume 33

Study: Popular tool for screening toddlers for autism spectrum disorders has low success rate

The most widely used tool for screening toddlers for autism spectrum disorders (ASD) misses many toddlers later diagnosed with the condition while incorrectly identifying ASD in a significant percentage of other children, according to a new study. 

Whitney Guthrie and colleagues examined the records of nearly 26,000 toddlers seen in the Children’s Hospital of Philadelphia network between January 2011 and July 2015. They found that 91 percent of the children were screened using the Modified Checklist for Autism in Toddlers with Follow-Up (M-CHAT/F). The American Academy of Pediatrics (AAP) recommends using this checklist to screen all toddlers for ASD at their 18- and 24-month checkups. 

The researchers found that the M-CHAT/F identified only about 40 percent of children who later received an ASD diagnosis. Moreover, of the children flagged as having ASD, only 15 percent later received an ASD diagnosis, although the majority of the others did have some type of developmental problem. 

The researchers also found that children from racial minority groups, from non-English speaking households, and from households with lower median incomes who received Medicaid were less likely to receive screening and more likely to receive a false positive score when they did get screened. In addition, the M-CHAT/F was less accurate for girls than for boys. 

Only half of the children were tested twice with the M-CHAT/F, as recommended by the AAP. The children who did get tested at two different ages were more likely to be correctly flagged with ASD. 

The researchers note that children who screened positive and did prove to have ASD received an official diagnosis seven months earlier than those who screened negative, indicating that screening may help some children who do have ASD receive treatment earlier. 

Guthrie comments, “Although our findings reveal significant shortcomings in current screening tools, we want to be clear that we are not recommending that pediatricians stop universal screening. Instead, clinicians should continue to screen using the MCHAT/F, while being aware that this screening tool does miss some children with ASD. Any clinical or parental concerns should be taken seriously, and warrant continued surveillance even if a child screens negative on the M-CHAT/F.” 

She adds, “Pediatricians should also be aware of disparities in screening practices and results in children of color and from low-income backgrounds.”


“First large-scale study of universal screening for autism raises critical questions about accuracy, equity,” news release, Children’s Hospital of Philadelphia, September 27, 2019. 


“Standard screen misses majority of toddlers with autism,” Lauren Schenkman, Spectrum News, September 27, 2017.