June 28, 2020
The CDC tracks autism prevalence in the U.S. to better understand the scope and impact autism has upon children, families, and communities. Additionally, service providers and organizations use these findings when preparing to meet the support needs of the families they serve. In this article, we will highlight some key information from the CDC's most recent autism prevalence report as well as answer some frequently asked questions about autism prevalence, such as: whether or not the increase in autism prevalence is due to better diagnosing, what causes autism, how the CDC determines autism rates, and more.
Current Autism Prevalence in the U.S.
The most recent report released by the CDC estimates that 1 in 54 children have autism in the United States, indicating a 178% increase in autism prevalence since 2000 when autism prevalence was 1 in 150.
Additional findings from the CDC's report show that:
- Most children are still diagnosed after the age of 4 even though they can be reliably diagnosed by age 2
- Boys are more than 4 times more likely to be identified with autism than girls
- While progress has been made to close racial and ethnic gaps in identifying those with autism, disparities still remain:
- Prevalence rates are similar between white and black children, but significantly lower for Hispanic children
- Black children with autism are less likely to be evaluated by age 3 than white children, and more likely to go without a diagnosis by 8 years
Frequently Asked Questions
Many people come to us with questions about autism prevalence. Below you will find answers to some of the most common questions we receive.
What causes autism?
While the cause of autism remains unclear, current studies show genetics and environment both play a role. The CDC also acknowledges that there are "many different factors that make a child more likely to have an ASD, including environmental, biologic and genetic factors," which is why they have launched the SEED study to learn more about the risk factors and causes of autism.
Is there really an increase in prevalence or is this just better diagnosing?
No. While it is true that the definition of autism was expanded to include PDD-NOS and Asperger's, the CDC states that:
"It is unclear exactly how much of this increase is due to a broader definition of ASD and better efforts in diagnosis. However, a true increase in the number of people with an ASD cannot be ruled out. We believe the increase in the diagnosis of ASD is likely due to a combination of these factors.
We do know that ASD are more common than we thought before and should be considered an important public health concern. There is still a lot to learn about ASD. In addition, increased concern in the communities, continued demand for services, and reports estimating a prevalence of about 1.7 percent show the need for a coordinated and serious national response to improve the lives of people with ASD.”National Center on Birth Defects and Developmental Disabilities. Centers for Disease Control and Prevention. Frequently Asked Questions: Is there an ASD Epidemic? 2019. www.cdc.gov/ncbddd/autism/topics.html.
There are a lot of different autism prevalence rates floating around out there. Which one is the official rate?
The prevalence rate that is considered “official” is the one that is released by the CDC.
Other organizations, such as the National Survey of Children’s Health (NSCH) and the National Health Interview Survey (NHIS), use different methods to collect their data and look at different age groups when determining prevalence rates. This is why their autism prevalence rates differ from the CDC’s.
The 1 in 54 rate doesn’t reflect what I see at my child’s school, so how do they come up with the rate?
Prevalence rates are not a census. They do not represent the entire population of children with autism in the United States. They are an estimate based on a sampling of communities throughout the United States.
Who is included in the CDC’s sample when they determine the rate?
The CDC calculates autism prevalence based on the following data:
- Health and special education records of 8-year-old children
- These records were collected from specific sites located in the following 11 states:
- New Jersey
- North Carolina
When did the CDC collect all of the data to determine the rate?
The CDC collected the data to determine the current rate back in 2016. It takes the CDC about 4 years to analyze the data and release a new prevalence rate.
What is the ADDM?
Back in 2000, the CDC created a monitoring network in order to track autism prevalence over time. This monitoring network is called the Autism and Developmental Disabilities Monitoring Network (ADDM). Before ADDM monitoring the CDC performed surveillance on the autism prevalence.
- 2020 Community Report on Autism from the CDC (March 2020)
- CDC Prevalence of Autism Spectrum Disorder Among Children Aged 8 Years for ADDM, 2016 (March 2020)
- CDC Early Identification of Autism Spectrum Disorder Among Children Aged 4 Years, Early ADDM, 2016 (March 2020)
- How the CDC Arrived at its 1 in 54 Estimate, and What it Means for Autism’s Present and Future (TACA Blog by Dr. Richard Frye April 2020)
- TACA's CDC Prevalence Report Archive