A study published recently in Pediatrics examined why some children initially receive negative results when screened for autism, yet later go on to be diagnosed with autism. The study assessed the profiles of more than 68,000 18-month-old children who had been deemed ‘not at risk’ for autism based on M-CHAT (Modified Checklist for Autism in Toddlers) screening by their parents. Of that group, 228 were later diagnosed with autism.
Researchers wanted to know more, so they reviewed additional screening information about development and temperament to see what might have been missed. They discovered that the children who were diagnosed with autism after the initial screening, had in fact presented behaviors associated with autism. These children were lagging in areas such as communication and fine motor skills, although the autism screener had failed to identify these developmental delays.
Screening for Autism – Girls vs. Boys
One interesting finding by the researchers was that girls were more likely than boys to falsely screen negative for autism at a young age. The girls who were incorrectly screened as ‘not at risk’ had different social behaviors that may have helped mask the disability. These girls exhibited less social inhibition and were less wary of strangers. These behaviors are largely inconsistent with the overall perception that children with autism are socially withdrawn and avoid interaction with others.
Given the critical importance of early diagnosis for any child on the autism spectrum, parents should understand the difference between basic screening and a more in-depth evaluation if they have concerns about their child, says Caravel Autism Health’s Dr. Eric Lund, a psychologist who has worked with children with autism for 15 years.
Is the M-CHAT Tool Reliable?
Most pediatricians rely on the M-CHAT tool during well-child visits to screen for early autism. And while the M-CHAT is an important means of identifying potential red flags in developmental progress, it has its limitations. For example, it relies heavily on the answers that parents provide to the pediatrician about the child’s behavior. As researchers noted in the recent study, parents may have difficulty recognizing and reporting some of the markers of autism, especially at very young ages.
“Parents should trust their instincts if they have concerns about their child’s developmental progress,” says Dr. Lund. “It is difficult to detect the subtler signals of developmental delays, especially in children as young as 18 months. But if a parent feels that something is not quite right, the best course of action may be to schedule a comprehensive diagnostic evaluation by a trained autism health professional.”
What is a Diagnostic Evaluation?
The diagnostic evaluation process is much more in-depth than a screening. Autism health specialists use a combination of questionnaires, diagnostic instruments and in-person observation to assess the child. At Caravel Autism Health, the parent and child meet with a psychologist and Board-Certified Behavior Analyst (BCBA) who may recommend additional tests such as the Vineland Adaptive Behavior Scales, Behavior Assessment System for Children (BASC), the Childhood Autism Rating Scale (CARS) and the Autism Diagnostic Observation Schedule (ADOS). Learn more about the evaluation and autism diagnostic process at Caravel.
“No screening or diagnostic tool is 100 percent effective,” explains Dr. Lund, “but the sooner a diagnosis is made, the sooner we can take action. ABA therapy is the most effective at early intervention, when it comes to improving communications skills and optimizing brain development.”
Caravel Autism Health has developed the Caravel Pediatric Development Screener© , which is available on our website. Please click here if you are wondering whether your child would benefit from a diagnostic evaluation for autism.
