Key Findings from the ADDM Network
A Snapshot of Autism Spectrum Disorder in 2014
Data from the Centers for Disease Control and Prevention’s Autism and Developmental Disabilities Monitoring (ADDM) Network help us understand more about the number of children with autism spectrum disorder (ASD), the characteristics of those children, and the age at which they are first evaluated and diagnosed. Read on to learn more about ASD across the ADDM Network.
How many children were identified with ASD?
About 1 in 59 or 1.7% of 8-year-olds were identified with ASD by the ADDM Network.
Boys were 4 times more likely to be identified with ASD than girls.
White children were still more likely to be identified with ASD than black or Hispanic children. Black children were more likely to be identified with ASD than Hispanic children. However, these differences were smaller when compared with estimates from previous years.
The percentage of children identified with ASD ranged widely across geographic areas.
For example, in the areas where the ADDM Network reviewed both health and special education records, the percentage of children who were identified with ASD ranged from a low of 1 in 77 or 1.3% in areas of Arkansas to a high of 1 in 34 or 3% in areas of New Jersey.
When were children evaluated and diagnosed?
…about 85 percent had developmental concerns by 3 years of age.
…but only about 42 percent received a comprehensive developmental evaluation by 3 years of age.
- About 42% of children identified with ASD were evaluated for developmental concerns by 3 years of age. This percentage is lower than the goal set by Healthy People 2020 that 47% of children with ASD have a first evaluation by 3 years of age.
- Even though ASD can be diagnosed as early as 2 years of age, most children were not diagnosed with ASD by a community provider until after 4 years of age.
- About 80% of children identified with ASD either had an
- Eligibility for autism-specific services within the special education program at school, or
- ASD diagnosis from a community provider.
- The remaining 20% of children were identified as having ASD by the ADDM Network based on ASD symptoms documented in their health and/or special education records but had not yet been recognized by a community provider as having ASD.
What was the intellectual ability of the children identified with ASD?
Among children identified with ASD who had intelligence quotient (IQ) scores available, nearly a third also had intellectual disability (IQ score ≤70). A quarter were in the borderline range for intellectual disability.
What effect did the recent change in diagnostic criteria have on prevalence estimates?
- In 2014, ASD prevalence was estimated using a surveillance case definition based on the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV-TR); ASD prevalence was also independently estimated using a new surveillance case definition based on the DSM-5 criteria.
- The new surveillance case definition included children who had documented symptoms consistent with the DSM-5 diagnostic criteria as well as children who had a previous ASD diagnosis, even if they didn’t have documentation of all the behavioral criteria.
- ASD prevalence was about 4% higher among children who met the DSM-IV-TR surveillance case definition compared to ASD prevalence among children who met the new DSM-5 case definition.