The rate of children diagnosed with autism in the United States has been growing steadily since 2000, but two new reports from the US Centers for Disease Control and Prevention highlight disparities in the types of children identified to have autism spectrum disorder and setbacks in early detection.
In 2020, about 1 in 36 children had been diagnosed with autism by age 8, according to the CDC -- about 2.8%. That's up from a prevalence of 1 in 44 children in 2018 and 1 in 150 children in 2000.
But according to the CDC, this long-term trend has "largely been interpreted as improvements in more equitable identification of (autism spectrum disorder), particularly for children in groups that have less access or face greater barriers in obtaining services."
For the first time, diagnosis was more common among Asian, Black and Hispanic children than it was among White children. The CDC researchers note that this shift "may reflect improved screening, awareness, and access to services among historically underserved groups." In fact, between 2018 and 2020, autism prevalence rose more than twice as fast among Asian, Black and Hispanic children than it did among White children.
These findings are based on surveillance data from 11 communities that participate in the CDC's Autism and Developmental Disabilities Monitoring Network. The data are not nationally representative and vary widely by location -- from a prevalence of 1 in 22 children in California to about half as many in Maryland. The CDC says more research is needed to understand this variation, which could be related to differences in the strategies used to identify and diagnose the condition.
Still, some trends have stayed consistent.
Autism prevalence is significantly higher among boys than girls -- in 2020, there was about a four-fold difference. But it was the first year that more than 1% of 8-year-old girls had been diagnosed with autism.
Also, disparities persist in identifying autism in children who also have an intellectual disability. In 2020, more than half of Black children diagnosed with autism also had an intellectual disability, compared with less than a third of White children. According to the researchers, this finding suggests a need to better detect and evaluate developmental concerns beyond cognitive ability.
Generally, children who have intellectual disabilities are more likely to be diagnosed with autism earlier. But early detection is important for all children with autism, as it helps connect them with helpful resources and interventions.
In recent years, good progress had been made in early detection of autism -- an earlier CDC report found that children born in 2014 were 50% more likely to receive an autism diagnosis or special education by age 4 than those born in 2010.
Another new report published by the CDC on Thursday shows that there was evidence of continued improvement in these trends through February 2020, but the trends reversed as the COVID-19 pandemic hit with "sustained lower levels" of evaluations and identification of autism across most of the surveillance network.
In first six months of the pandemic, there were 217 fewer evaluations for every 1,000 children at age 4 than there were four years earlier. There were also nearly three fewer identifications for every 10,000 children, according to the CDC report.
"Disruptions due to the pandemic in the timely evaluation of children and delays in connecting children to the services and support they need could have long-lasting effects," said Dr. Karen Remley, director of CDC's National Center on Birth Defects and Developmental Disabilities. "The data in this report can help communities better understand how the pandemic impacted early identification of autism in young children and anticipate future needs as these children get older."