The rate of 8-year-olds in the United States diagnosed with autism rose in 2018, to about 1 in 44, according to data tracked by the Centers for Disease Control and Prevention — an increase attributed to better access to early interventions that result in more comprehensive identification of the condition.
A March 2020 report from the CDC estimated that 1 in 54 8-year-olds had received an autism diagnosis. Between the release of that report and the findings presented this month, the prevalence of autism increased from about 1.9 percent to 2.3 percent of children in that age group.
“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,” Karen Remley, director of CDC’s National Center on Birth Defects and Developmental Disabilities, said in a statement. “Accessing these services at younger ages can help children do better in school and have a better quality of life.”
The federal agency collects data from 11 communities in Arizona, Arkansas, California, Georgia, Maryland, Minnesota, Missouri, New Jersey, Tennessee, Utah and Wisconsin. Though those communities are not a representative sample of the U.S. population, researchers have tracked changes in autism prevalence in those areas since 2000 to understand the developmental condition over time.
The latest report found that autism rates varied greatly throughout the United States. California had the highest incidence rate, with 1 in 26 8-year-olds receiving a diagnosis. Missouri had the lowest rate, with 1 in 60 children in that age group assessed with the condition. The report said those differences may reflect how communities identify children with autism because some regions have more services for children with autism and their families.
Andy Shih, interim chief science officer at the advocacy group Autism Speaks, agreed that regional differences may be tied to more robust services in some of the 11 locations studied by the CDC, which tend to draw families seeking treatment options for their children.
“We often hear about parents moving to a state where it’s easier for them to access services and regular support,” Shih said.
Some experts caution that the way the CDC collects data could skew the numbers and make it seem like autism is more common than it is. Developmental psychologist Bryna Siegel warned that the CDC is likely overcounting autism cases in many places.
In some states, an autism diagnosis is often a path to affordable services for a child with special needs. That dynamic can create an ethical dilemma for doctors who want to help families find services to improve a child’s quality of life.
“If a child gets a diagnosis of a language disorder, maybe he’ll get group speech therapy once a week when he goes to Head Start, but if you say that he has autism, he might get home-based one-to-one applied behavior analysis services for 25 hours a week,” said Siegel, executive director of the Autism Center of Northern California, an assessment clinic that provides services to children with autism. “And, truthfully, any kid is going to do better with 25 hours a week of one-to-one service than with a 20-minute group speech therapy session each week.”
Because doctors want to connect patients with the best services available, they may be inclined to justify an autism diagnosis so that children can get access to the services that come with it.
“And so clinicians are put in a terrible bind to use the diagnosis of autism,” Siegel said.
A CDC epidemiologist said the agency’s data reflects practices and services.
“There is not a universal and objective ‘gold standard’ diagnostic procedure; there is variability in diagnostic practices and policies, and experts (and diagnostic instruments) can disagree on their conclusions,” Matt Maenner, an epidemiologist for the CDC’s National Center on Birth Defects and Developmental Disabilities, said in an email. “The [Autism and Developmental Disabilities Monitoring] Network data allow people to see what is happening in their communities, including how and when children are identified as having autism.”
Maenner said issues with improper diagnoses should be addressed by providers, and would not affect how the agency collects data.
“If the data raise questions about how communities are identifying children with autism, it would seem better to work to improve practices rather than adjust the surveillance data to mask these issues,” Maenner added.
Still, the CDC’s data gives some insight into who is being diagnosed with autism and where.
Boys were four times more likely to be diagnosed with autism than girls — a trend that has held up since the CDC began collecting data on the condition in 2000. The researchers found few differences in prevalence based on race, with similar rates among 8-year-olds in Black, White, and Asian or Pacific Islander communities. Fewer Hispanic children were diagnosed with autism compared with other groups, according to the report. The data showed that about one-third of the children diagnosed with autism also had an intellectual disability.
Shih said the CDC’s study suggests that efforts to expand early intervention have been succeeding, but some states could be doing more to reach children in underserved and lower-income communities.
“It’s really imperative for us trying to identify children as early as possible, to get them into support and services,” he added.
In additional findings regarding children who turned 4 years old in 2018 in those same 11 communities, new patterns in diagnosis emerged, according to the CDC. There were more diagnoses among Black, Hispanic, and Asian or Pacific Islander children than among White children in that cohort. Lower-income neighborhoods also had higher prevalence rates, the agency said.
Those children who were born in 2014 were 50 percent more likely to have received a diagnosis by their fourth birthday, compared with children who were born in 2010. The researchers said that data reflected improved access to early intervention, which can help children with autism thrive later in life.
“We’re doing a better job for the younger kids,” Shih said.