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April 13, 2016

Researchers still don't know why N.J. has highest autism rate in country

Latest report puts New Jersey autism prevalence at 1 in 41 children

While 1 out of 68 kids nationwide is diagnosed with Autism Spectrum Disorder (ASD), in New Jersey it's 1 out of 41. That statistic, released in a new report from the Centers for Disease Control, represents a 12 percent increase over just two years.

Do those numbers mean that something's wrong in New Jersey — or that the state is doing something right?

"We do see that the rate is increasing over time. We know some of the increase is due to better awareness and more thorough record-keeping," said Suzanne Buchanan, executive director of the 50-year-old advocacy group Autism New Jersey.

Thorough record-keeping is something that New Jersey has a good reputation for.

"New Jersey has been pretty well known for having good early detection across educational and pediatric settings. I don't know that Pennsylvania has the same reputation for conducting early screening," said psychologist James Connell, a director at Drexel University's Autism Institute.

However, it doesn't completely explain the high prevalence of autism in New Jersey.

"Access to a full range of professional (health and educational) evaluations plays a tremendous role in the completeness of autism case-finding ... still, you see that New Jersey’s 2.5 percent ASD prevalence is significantly higher than ASD prevalence in states with comparable access to records," said Dr. Walter Zahorodny of Rutgers in a Q&A published on

Zahorodny led the New Jersey portion of the CDC study, which examined records on 32,000 8-year-olds in Essex, Hudson, Union and Ocean counties.

Related story: Drexel professor urges universal autism screening despite lack of national recommendation

Researchers in the study conducted a systematic review of health and special education records in 11 states that are part of the Autism and Developmental Disabilities Monitoring (ADDM) network.

They measured both the prevalence of autism and the percent of children with ASD who had gotten a comprehensive evaluation by age three, or at least had concerns recorded in their educational or health records. Early screening and detection are crucial because treatment is more effective when children are younger.

New Jersey has consistently had higher autism diagnosis rates than the other 10 states, for reasons that researchers cannot explain. Even states like Maryland and North Carolina which appear to be more thorough than New Jersey when it comes to early detection have lower rates of autism prevalence.

State Concerns Evaluation PrevalenceAge of  diagnosis
Arizona  90%39% 1 in 66 4 years, 7 months 
Arkansas 88%24% 1 in 835 years
Colorado 86%41%1 in 924 years, 7 months 
 Georgia 88% 41%1 in 64  4 years, 3 months
 Maryland 95% 55%1 in 55 3 years, 9 months 
 Missouri83% 41%1 in 87  4 years, 2 months
 New Jersey82%43% 1 in 41  3 years, 11 months
 North Carolina92% 60%1 in 59  4 years
 South Carolina92% 39% 1 in 81  4 years
 Utah81%  38%1 in 58  4 years, 2 months
 Wisconsin90%  42% 1 in 92 4 years, 2 months

Above: Percent of children with Autism Spectrum Disorder who had concerns noted in educational or medical records by age 3; percent who had comprehensive evaluation by age 3; prevalence among 8-year-olds; median age of diagnosis. 

"We do not understand why the ASD rate increased again in New Jersey or why it has been increasing across the ADDM Network over the past decade," said Zahorodny.

Factors associated with a higher risk of autism include increased parental age, maternal illness during pregnancy and genetic mutations. A study that claimed that autism was linked to vaccines was debunked as a fraud.

"The best available research to date has not identified a specific environmental trigger or cause," said Buchanan.

The data also shows some other disparities in who gets diagnosed. Nationally, boys were 4.5 times more likely than girls to have an autism diagnosis. White children were 50 percent more likely to be diagnosed than Hispanic children, and 20 percent more likely than black children.

Whatever the cause, the prevalence of autism in New Jersey is likely to only climb higher. As Zahorodny concluded: "Still-higher autism rates are inevitable."

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