One in 44 8-year-old children has been identified as having autism spectrum disorder, a rate that continues to rise and indicates a need to make sure supports are in place for them, experts said.
The rate reported Thursday in the Morbidity and Mortality Weekly Report is up from one in 54 children two years prior. Experts said they can’t rule out environmental factors contributing to the increase but also pointed to improvements in screening and diagnosing children.
“There’s a ton of added initiatives and effort around screening and identification in large part due to the AAP’s advocacy efforts as well as leadership in the autism space,” said Kristin Sohl, M.D., FAAP, chair of the AAP Council on Children with Disabilities Autism Subcommittee. “That’s obviously going to lead to more kids who are being evaluated, so that leads to more diagnoses.”
The AAP recommends developmental screenings at 9, 18 and 30 months and screening for autism at ages 18 and 24 months.
About 47% of 8-year-olds with autism were evaluated by 36 months, up from 44% two years prior, according to the report from the Centers for Disease Control and Prevention (CDC). An accompanying report also found children born in 2014 were 50% more likely to have an autism diagnosis by 4 years compared to children born in 2010.
“The substantial progress in early identification is good news because the earlier that children are identified with autism, the sooner they can be connected to services and support,” National Center on Birth Defects and Developmental Disabilities Director Karen Remley, M.D., M.P.H., M.B.A., FAAP, said in a press release. “Accessing these services at younger ages can help children do better in school and have a better quality of life.”
The CDC’s findings are based on 2018 data from its Autism and Developmental Disabilities Monitoring Network, which spans 11 sites — Arizona, Arkansas, California, Georgia, Maryland, Minnesota, Missouri, New Jersey, Tennessee, Utah and Wisconsin. While reports from the network may not be nationally representative, they are commonly used as an indicator of autism prevalence. The 2018 analysis used a new case definition, but applying that definition to the 2016 data still showed an increase.
The prevalence rates among 8-year-olds at the 11 sites ranged from one in 61 in Missouri to one in 26 in California. The rate for boys was four times higher than the rate for girls, consistent with previous years. While that trend may be starting to shift, many girls with autism likely are still being missed because their expected behavior is different than that of boys and they may be better at camouflaging their symptoms, said Dr. Sohl, executive director of ECHO Autism and professor of clinical child health at the University of Missouri.
“The bottom line is we as clinicians, as experts, have to get very good at recognizing this autism spectrum looks different in girls,” she said. “We cannot keep missing it.”
Autism rates for Hispanic children were lower than those of White and Black children at some sites, indicating a potential disparity in screening. In addition, Black children identified as having autism were more likely to have an intellectual disability than children who are Hispanic or White. This may indicate some aren’t being diagnosed unless the severity of their condition makes it obvious, according to Dr. Sohl.
Overall, about 35% of the children with autism had an intellectual disability and tended to be diagnosed earlier than children without an intellectual disability.
Dr. Sohl said the data should be used to ensure supports are in place for this growing number of children diagnosed with autism. She called for state and federal advocacy to make sure Medicaid and private insurance cover medically necessary services. She also called on pediatricians to know the signs of autism and act on them.
“General pediatricians are very critical to addressing this need,” she said. “With more children being diagnosed, that tells me pediatricians are doing more and more to screen and identify these kiddos. And I think the more that pediatricians engage in understanding autism, the more that pediatricians can play a role in community-based diagnosis.”