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Autism Prevalence Is Up, CDC Report Shows

— But early evaluations in young children started to fall as pandemic set in

MedpageToday
A photo of a female psychologist evaluating a little boy with autistic behaviors.

An estimated 2.8% of 8-year-old children were identified with autism spectrum disorder (ASD) in the Autism and Developmental Disabilities Monitoring () network in 2020, CDC data showed.

That prevalence -- roughly 4% of boys and 1% of girls -- is higher than a previous estimate that identified autism in 2.3% of 8-year-olds in 2018, according to an analysis in (MMWR).

The findings come from 11 communities in the ADDM network of data about 8-year-old and 4-year-old children in Arizona, Arkansas, California, Georgia, Maryland, Minnesota, Missouri, New Jersey, Tennessee, Utah, and Wisconsin.

The ADDM network has reported an among 8-year-olds since 2000. The data are not representative of the entire U.S., the CDC said.

A second of 2020 ADDM data suggested that in the early months of the COVID-19 pandemic, 4-year-olds were less likely to have an evaluation or be identified with autism than 8-year-olds when they were the same age.

"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 Karen Remley, MD, director of the CDC's National Center on Birth Defects and Developmental Disabilities, in a statement.

"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," Remley added.

In 2020, autism prevalence among 8-year-olds in the ADDM communities ranged from 2.3% in Maryland to 4.5% in California. Prevalence rose more sharply among Asian, Black, and Hispanic children, where it was at least 30% higher in 2020 than 2018. Among white children, it was 14.6% higher than in 2018.

For the first time, the percentage of 8-year-old Asian (3.3%), Hispanic (3.2%), or Black (2.9%) children with autism was higher than among white children of the same age (2.4%).

"This is the opposite of racial and ethnic differences observed in previous ADDM reports for 8-year-olds," CDC authors wrote. "These shifts may reflect improved screening, awareness, and access to services among historically underserved groups."

Across the ADDM sites, autism prevalence was nearly four times higher for 8-year-old boys than girls, and 2020 was the first year in which more than 1% of girls were identified with autism, the CDC said.

Among children with autism who had cognitive ability data, 37.9% were identified as having a co-existing intellectual disability, which ranged from 31.8% of white children to 50.8% of Black children. Children with intellectual disability had earlier median ages at autism diagnosis than those without intellectual disability (43 vs 53 months).

Among 4-year-olds, the overall prevalence of autism was 2.2% in 2020; it was higher among boys than girls at every ADDM site. Prevalence ranged from 1.3% in Utah to 4.6% in California.

In the 6 months before the pandemic was declared, there were 1,593 more evaluations and 1.89 more autism identifications per 1,000 children at age 4 than there had been 4 years earlier. In the 6 months after pandemic onset, the pattern reversed: there were 217 fewer evaluations and 0.26 fewer identifications per 1,000 children age 4 compared with 4 years before.

"Patterns of evaluation and identification varied among sites, but there was not recovery to pre-COVID-19 pandemic levels by the end of 2020 at most sites or overall," the CDC authors noted.

"Communities could evaluate the impact of these disruptions as children in affected cohorts age and consider strategies to mitigate service disruptions caused by future public health emergencies," they added.

  • Judy George covers neurology and neuroscience news for ֱ, writing about brain aging, Alzheimer’s, dementia, MS, rare diseases, epilepsy, autism, headache, stroke, Parkinson’s, ALS, concussion, CTE, sleep, pain, and more.

Disclosures

No potential conflicts of interest were disclosed.

Primary Source

Morbidity and Mortality Weekly Report

Maenner MJ, et al "Prevalence and characteristics of autism spectrum disorder among children aged 8 years -- Autism and Developmental Disabilities Monitoring network, 11 Sites, United States, 2020" MMWR 2023; DOI: 10.15585/mmwr.ss7202a1.

Secondary Source

Morbidity and Mortality Weekly Report

Shaw KA, et al "Early identification of autism spectrum disorder among children aged 4 years -- Autism and Developmental Disabilities Monitoring network, 11 sites, United States, 2020" MMWR 2023; DOI: 10.15585/mmwr.ss7201a1.