The latest estimate is higher than the prevalence in the CDC’s 2016 report (1 in 68 children).
In Wisconsin, where ASD prevalence continues to be lower than the national level, the number of children with autism increased from 1 in 92 in the 2016 report to 1 in 71 in the 2018 report. This rate corresponds to 1.4% of school-aged children.
“The prevalence of autism in Wisconsin has nearly tripled since 2002, the year we began monitoring it in our state. The ability to identify rates and trends specific to Wisconsin is useful for planning and delivering services to meet local needs,” says Maureen Durkin, a Waisman Center researcher and professor and chair of population health sciences at the University of Wisconsin-Madison.
Data for the new report come from the CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network – a tracking system that provides estimates of the prevalence and characteristics of ASD among more than 300,000 8-year-old children from 11 communities across the United States, including ones in Wisconsin.
Durkin is the principal investigator of the Wisconsin Surveillance of Autism and Other Developmental Disabilities System (WISADDS), one of the 11 ADDM Network sites. Findings from WISADDS contributed the Wisconsin data used in the CDC report.
ADDM is the largest population-based program to monitor autism and the only autism tracking system that examines health and education records. The ADDM Network estimates are combined from communities in Arizona, Arkansas, Colorado, Georgia, Maryland, Minnesota, Missouri, New Jersey, North Carolina, Tennessee, and Wisconsin. The communities surveyed in this report are home to about 8 percent of 8-year-old children in the United States.
Estimates of autism varied widely among the 11 communities in this report, although five reported similar estimates of 1.3 to 1.4 percent. The highest prevalence estimate of 2.9 percent came from a community in New Jersey. Some of the regional differences in autism prevalence estimates among the communities might be due to differences in how autism is being diagnosed and documented.
“Autism prevalence among black and Hispanic children is approaching that of white children,” said Stuart Shapira, MD, PhD, associate director for science at CDC’s National Center on Birth Defects and Developmental Disabilities. “The higher number of black and Hispanic children now being identified with autism could be due to more effective outreach in minority communities and increased efforts to have all children screened for autism so they can get the services they need.”
The data demonstrate that more work needs to be done to identify children with autism at a younger age and refer them for early intervention. Findings show that fewer than half of the children identified in the ADDM Network received their first autism diagnosis by the time they were 4 years old.
Although 85% of children with autism had concerns about their development noted in their health records by the time they were 3 years old, only 42% received a developmental evaluation by that age. This lag between first concern and first evaluation may affect when children with autism can begin getting the services they need.
“As a parent of a child with autism, I’m grateful to have this data on autism prevalence and how we’re doing at identifying autism early,” says Gail Chödrön, PhD, the CDC’s Act Early Ambassador to Wisconsin. “We have the tools we need to identify autism concerns at a young age, and we can all play a part. The CDC’s Learn the Signs. Act Early materials help parents and providers track a child’s development so they can identify concerns early. In Wisconsin, we’re lucky that these materials are readily available and widely used.”