Key Findings from the ADDM Network

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A Snapshot of Autism Spectrum Disorder in 2018

Data from the 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 in communities across the ADDM Network.

1 in 44 8-year-old children were identified with ASD in 2018

How many 8-year-old children were identified with ASD in 2018?

About 1 in 44 (2.3%) 8-year-old children were identified with ASD by the ADDM Network.

Percentage of 8-year-old children identified with ASD by ADDM Network Site

Percentage of 8-year-old children identified with ASD by ADDM Network Site

How did the percentage of children identified with ASD vary across geographic areas?

The percentage of children identified with ASD varied widely across geographic areas.

Across the ADDM Network, the percentage of 8-year-old children who were identified with ASD ranged from a low of 1.7% or 1 in 60 children in Missouri to a high of 3.9% or 1 in 26 children in California. Sites with limited or no direct access to special education records had lower percentages of children identified with ASD.

Which children were more likely to be identified with ASD?

Among 8-year-old children, boys were more than 4 times as likely to be identified with ASD as girls.

The ADDM Network found no overall difference in the percent of Black, White, Hispanic, and Asian or Pacific Islander 8-year-old children identified with ASD. However, at several sites, the percent of Hispanic children identified with ASD was lower compared with Black or White children.

chart 8-year-old boys were more than 4x as likely to be identified with ASD as girls.
Approximately 1/3 of 8-year-old children identified with ASD also had intellectual disability

What was the intellectual ability of the children identified with ASD?

Among 8-year-old children identified with ASD who had intelligence quotient (IQ) scores available, approximately one-third (35.2%) also had intellectual disability.

72% of 4-year-old children with ASD in 2018 received a developmental evaluation by 36 months of age

Cumulative incidence of ASD identified per 1000 children.

Cumulative incidence of ASD identified per 1000 children.

When were children evaluated and diagnosed?

Findings from the ADDM Network show that 72% of 4-year-old children with ASD in 2018 received a developmental evaluation by 36 months of age.

More children who were born in 2014 (1.36%) received an ASD diagnosis or ASD special education classification by 48 months of age compared to children born in 2010 (0.89%).