Researchers estimate the prevalence of autism spectrum disorder was 3.14% among children and adolescents in the United States in 2019 and 2020. Photo by PhotoUG/Shutterstock
July 5 (UPI) -- A new study estimates the prevalence of autism spectrum disorder at 3.14% among children and adolescents in the United States in 2019 and 2020, a rising trend.
The study, published online Tuesday in JAMA Pediatrics, said this finding, derived from nationally representative data in the United States, was higher than the reported prevalence of the disorder from other surveys.
Those included the National Health Interview Survey in 2014 to 2016 (2.47%), the Centers for Disease Control and Prevention's Autism and Developmental Disabilities Monitoring Network in 2018 (2.30%) and the National Survey of Children's Health in 2016 (2.50%).
Researchers described the disorder as "a complicated neurodevelopmental disability with an increasing prevalence worldwide."
They noted that their estimate for autism spectrum disorder in the United States is higher than what's been reported in study estimates worldwide published since 2014, ranging from 0.42% to 3.13% in Europe, 0.11% to 1.53% in the Middle East, and 1.41% to 2.52% in Australia.
Nationwide, roughly 1 in 44 children was identified with autism spectrum disorder in 2018, according to the CDC's latest data, up from one in 150 children in 2000.
CDC says the condition occurs across racial, ethnic and socioeconomic groups, and is more than four times more common in boys than girls.
For the new study, scientists used data from the National Health Interview Survey indicating that 410 of 12,554 children and adolescents ages 3 to 17 had a diagnosis of autism spectrum disorder, also finding a higher prevalence in boys than in girls. From this they calculated the national rate.
The prevalence of autism spectrum disorder was 2.79% in 2019, 3.49% in 2020 and 3.14% for both years combined, the scientists said.
The study also found that varying economic status played a role, with a higher prevalence of the disorder among low-income families.
"I do not see these findings as surprising for a few reasons," Arun Karpur, director of data and science evaluation research at Autism Speaks, told UPI.
He explained that the way in which the survey captures data is different from how previous studies on prevalence have captured data. Certain variables, such as the sampling and reporting systems leveraged to collect data for this study, may have resulted in higher prevalence numbers.
For example, he explained that data from the National Health Interview Survey covers children from ages 3 to 17. So, he said, these data are "more likely to document a higher proportion prevalence" compared to the CDC's network data that reports on the prevalence only among 8-year-old children.
Further, Karpur noted that the sampling approach in the survey used by the researchers is based on one self-reported question, "and is likely to be affected by the bias among responding parents."
In other words, these factors may have produced skewed numbers that would seem to indicate a higher prevalence rate/increase, Karpur said.
And yet, "while the prevalence increase outlined in this study might not be exact or entirely representative of the real numbers," various studies in recent years have also indicated an increase in prevalence of the disorder, Karpur explained.
This can be "attributed to increased awareness, testing and diagnosis in communities, as well as the understanding that children with an official autism diagnosis have access to more resources and supports that benefit families," he said.