Investigators found that up to 10% of children in some of the state’s school districts have an ASD diagnosis vs. the national average of just under 2%.
School districts with higher ASD prevalence in the study have expansive health and educational programs in place to diagnose and support children with ASD, which likely contributed to the higher caseloads, senior investigator Walter Zahorodny, PhD, associate professor of pediatrics at New Jersey Medical School in Newark, said in an interview.
“When you have those players on the ground, it’s likely we’re going to be finding more, if not almost all, of the children with autism in a given district,” said Dr. Zahorodny, director of the New Jersey Autism Study for the Centers for Disease Control and Prevention.
The study was published online Oct. 21 in the journal Autism Research.
Local analysis
Researchers used the Autism and Developmental Disabilities Monitoring (ADDM) Network, a surveillance method developed by the CDC that includes data collected from health and special education records of children living in 11 communities across the United States. New Jersey is one of the ADDM participating sites.
National data are important, but Dr. Zahorodny and colleagues wanted to examine ASD prevalence at a more granular level, comparing prevalence district by district.
They examined data from 5,453 children who were 8 years old in 2016 and attended public school in Essex, Hudson, Ocean, and Union counties.
The prevalence of ASD was 36 children per 1,000 overall. Hudson County reported the lowest rate, at 31 cases per 1,000 children, and Ocean County reported the highest, at 54 cases per 1,000 children.
Across the region, ASD prevalence was four times higher in boys vs. girls, mirroring national statistics.
High ASD prevalence was more likely in mid-socioeconomic status districts (prevalence ratio [PR], 1.2; P = .01) and in larger school districts (PR, 1.3; P = .004).
Hispanic children had significantly lower ASD prevalence overall compared with White children (PR, 0.6; P < .001). In fact, prevalence was 30%-60% lower among Hispanic children in three of four counties compared with White children.
Another study is underway to better understand why autism rates were lower in specific districts and Hispanic children overall, but Dr. Zahorodny said one possibility is a lack of resources in those districts.
Will new methodology miss cases?
The study’s methodology was used by the CDC from 2000 to 2016 and includes assessment of children who have an ASD diagnosis, and children who haven’t received a diagnosis but have documented behaviors consistent with ASD.
In 2018, it was replaced with a less comprehensive approach that relies only on children with an ASD diagnosis. Data using this new methodology have not yet been reported.
In the new study from New Jersey, 767 children with autism were diagnosed by a pediatrician, neurologist, or other community provider. The remaining 175 children with autism, 18.6% of the total cohort, did not have an ASD diagnosis but met the ADDM case definition.
Under the new methodology, those children would not be counted.
“Something could be lost in the new methodology in terms of usefulness of the information because when the estimates are incomplete or low, that might lead people to make the wrong judgments when they make decisions about resources,” Dr. Zahorodny said.
The study was funded by the Centers for Disease Control and Prevention and the National Institutes of Health. The study authors report no relevant financial relationships.
A version of this article first appeared on Medscape.com.