Pediatricians, Specialists Largely Agree on ASD Diagnoses

General pediatricians and a multidisciplinary team of specialists agreed most of the time on which children should be diagnosed with autism spectrum disorder (ASD), data from a new study suggest.

But when it came to ruling out ASD, the agreement rate was much lower.

The study by Melanie Penner, MSc, MD, with the Autism Research Centre at Bloorview Research Institute, Toronto, and colleagues found that 89% of the time when a physician determined a child had ASD, the multidisciplinary team agreed. But when a pediatrician thought a child did not have ASD, the multidisciplinary team agreed only 60% of the time. The study was published in JAMA Network Open.

Multidisciplinary team model can't keep up with demand

The findings are important as many guidelines recommend multidisciplinary teams (MDTs) for all ASD diagnostic assessment. However, the resources for this model can't meet the demand of children needing a diagnosis and can lead to long waits for ASD therapies.

In Canada, the researchers note, the average wait time from referral to receipt of ASD diagnosis has been reported as 7 months and "has likely lengthened since the COVID-19 pandemic."

Jennifer Gerdts, PhD, an attending psychologist at the Seattle Children's Autism Center, said in an interview that the wait there for diagnosis in children older than 4 is "multiple years," a length of time that's common across the United States. Meanwhile, in many states families can't access services without a diagnosis.

Expanding capacity with diagnoses by general pediatricians may improve access, but the diagnostic accuracy is critical.

Dr. Gerdts, who was not part of the study, said this research is "hugely important in the work that is under way to build community capacity for diagnostic evaluation."

She said this study shows that not all diagnoses need the resources of a multiple-disciplinary team and that "pediatricians can do it, too, and they can do it pretty accurately." Dr. Gerdts evaluates children for autism and helps train pediatricians to make diagnoses.

Pediatricians, specialist team completed blinded assessments

The 17 pediatricians in the study and the specialist team independently completed blinded assessment and each recorded a decision on whether the child had ASD. The prospective diagnostic study was conducted in a specialist assessment center in Toronto and in general pediatrician practices in Ontario from June 2016 to March 2020.

Children were younger than 5.5 years, did not have an ASD diagnosis and were referred because there was a development concern. The pediatricians referred 106 children (75% boys; average age, 3.5 years). More than half (57%) of the participating children were from minority racial and ethnic groups.

The children were randomly assigned to two groups: One included children who had their MDT visits before their pediatrician assessment and the other group included those who had their MDT visits after their pediatrician assessment.

The MDT diagnosed more than two-thirds of the children (68%) with ASD.

Sensitivity and specificity of the pediatrician assessments, compared with that of the specialist team, were 0.75 (95% confidence interval, 0.67-0.83) and 0.79 (95% CI, 0.62-0.91), respectively.

A look at pediatricians' accuracy

Pediatricians reported the decisions they would have made had the child not been in the study.

In 69% of the true-positive cases, pediatricians would have given an ASD diagnosis.
In 44% of true-negative cases, they would have told the family the child did not have autism; in 30% of those case, they would give alternative diagnoses (most commonly ADHD and language delay).
The pediatrician would have diagnosed ASD in only one of the seven false-positive cases and would refer those patients to a subspecialist 71% of the time.
In false-negative cases, the pediatrician would incorrectly tell the family the child does not have autism 44% of the time.

Regarding the false-negative cases, the authors wrote, "more caution is needed for pediatricians when definitively ruling out ASD, which might result in diagnostic delays."

Confidence is key

Physician confidence was also correlated with accuracy.

The authors wrote: "Among true-positive cases (MDT and pediatrician agree the child has ASD), the pediatrician was certain or very certain 80% of the time (43 cases) and the MDT was certain or very certain 96% of the time (52 cases). As such, if pediatricians conferred ASD diagnoses when feeling certain or very certain, they would make 46 correct diagnoses and 2 incorrect diagnoses."

The high accuracy of diagnosis when physicians are confident suggests "listening to that sense of certainty is important," Dr. Gerdts said. Conversely, these numbers show when a physician is uncertain about diagnosing ASD, they should listen to that instinct, too, and refer.

The results of the study support having general pediatricians diagnose and move forward with their patients when the signs of ASD are more definitive, saving the less-certain cases for the more resource-intensive teams to diagnose. Many states are moving toward that "tiered" system, Dr. Gerdts said.

"For many, and in fact most children, general pediatricians are pretty accurate when making an autism diagnosis," she said.

"Let's get [general pediatricians] confident in recognizing when this is outside their skill and ability level," she said. "If you're not sure, it is better to refer them on than to misdiagnose them."

The important missing piece she said is how to support them "so they don't feel pressure to make that call," Dr. Gerdts said.

This project was funded by a grant from the Bloorview Research Institute, a grant from the Canadian Institutes of Health Research and a grant from the Canadian Institutes of Health. Three coauthors consult for and receive grants from several pharmaceutical companies and other organizations. Dr. Gerdts declared no relevant financial relationships.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.

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