Autism Prevalence Rate
According to the Centers for Disease Control and Prevention (CDC) the national rate of children identified with Autism Spectrum Disorder is 1 in 59 children. This statistic is based on their evaluation of health and educational records of 8-year-old children in 2014 in 11 states, including New Jersey. New Jersey has the highest rate of autism in the nation: 1 in 34 children, or 3% of 8-year-old children. New Jersey’s prevalence continues to exceed and outpace other states. Minnesota is the next highest at 1 in 42.
Why the increase and why is New Jersey the highest?
The New Jersey study’s lead investigator, Dr. Walter Zahorodny, an Associate Professor at Rutgers New Jersey Medical School, suggests the higher rate in New Jersey is likely due to more people knowing about autism and referring children to experts to document their concerns. These detailed reports then provide the investigators a more complete picture of children’s challenges and possible diagnoses. Without as many reports, “other states could be underestimating the rate of autism,” he stated.
Certainly, greater awareness and public health education by the government and advocacy groups like Autism New Jersey and our partners contribute to the increase. New Jerseyans also have more access to diagnostic services, so more children are getting evaluated.
Known risk factors such as prematurity, low birth weight, multiples, and advanced maternal age could contribute to the higher prevalence rate. For example, New Jersey has a much higher rate of births to women over the age of 35. The Department of Health’s Autism Registry Brief outlines these risk factors for autism and how New Jersey compares to the national averages.
Other Notable Takeaways
Historically in New Jersey, black and Hispanic children were diagnosed less often and at later ages than their white peers. For the 2014 cohort in New Jersey and the first time ever, there were no racial disparities as the prevalence in each ethnic group was nearly identical, demonstrating that public awareness about autism has reached and has galvanized minority communities.
Nationally, disparities in the evaluation and diagnosis of ASD across racial backgrounds continue to persist. For example, children with ASD from black and Hispanic communities were less likely to receive a professional evaluation before 36 months. Nationally, the differences between black and white children decreased in most sites from previous reports, but remained notable for Hispanic children.
New Jersey is doing a better job of identifying girls with a ratio of 3.7 (boys) to 1 (girls). This trend is also seen at the national level with a ratio of 4:1 (previously 4.5:1).
Among New Jersey children who had IQ scores available, 28% also have an intellectual disability. This percentage is consistent with national figures. Also, more children with average IQ are being identified as having autism.
Age of Diagnosis:
Even though ASD can be diagnosed as early as age 2, most children were not diagnosed with ASD by a community provider until ages 3 to 5, depending on how ASD presented itself. No improvement from the previous study was seen on diagnosing autism earlier. This could be due in part to more children with higher IQs being identified whose deficits may surface at a later date. Nevertheless, the goal remains to diagnose ASD as early as possible to ensure children have access to intensive, evidence-based treatment.