Key Findings from the ADDM Network: A Snapshot of
Autism Spectrum Disorder
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 across the ADDM Network.

How many children were identified with ASD?
About 1 in 68 or 1.5% of 8-year-olds were identified with ASD by the ADDM Network.

1IN
68

How did the percentage of children identified with ASD range across geographic areas?
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 81 or 1.2% in areas of
South Carolina to a high of 1 in 41 or 2.5% in areas of
New Jersey.

WI

UT

NJ
CO

MD

MO
NC

AZ

AR

SC
GA

1% – 1.4%
1.5% – 1.9%
2% – greater

Which children were more likely to be identified with ASD?
Boys were 4.5 times more likely to be identified with
ASD than girls.

White children were 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.

1.2x
1.5x
1.3x

among white vs
MORE LIKELY black children
among white vs
MORE LIKELY Hispanic children
among black vs
MORE LIKELY Hispanic children

Centers for Disease Control and Prevention • Community Report on Autism • 2016

 What was the intellectual ability of the children identified with ASD?
Among children identified with ASD who had IQ scores available, about a third also had intellectual disability.
Average or
above average
intellectual ability

Intellectual
disability

44%

32%
24%

Borderline
range

* Based on information from the 9 ADDM Network sites that had intelligence quotient (IQ) scores available for at least 70% of children identified with
ASD. Intellectual disability defined as IQ score ≤70.

When were children evaluated and diagnosed?
•  About 43% of children identified with ASD were evaluated for developmental concerns by
age 3 years. This percentage is lower than the goal set by Healthy People 2020 that 47% of
children with ASD have a first evaluation by age 3 years.
•  Black and Hispanic children were less likely to be evaluated for developmental concerns by
age 3 years than white children.
•  Even though ASD can be diagnosed
as early as age 2 years, most
children were not diagnosed with
ASD by a community provider until
after age 4 years.

ASD Subtype
Autistic disorder

Median* Age of Diagnosis
3 years, 10 months

Pervasive developmental disordernot otherwise specified (PDD-NOS)

4 years, 1 month

Asperger disorder

6 years, 2 months

* Median is the number in the “middle” within a sorted list of number from highest
to lowest.

•  About 82% of children identified with ASD either had an
o  Eligibility for autism-specific services within the special education program at school, or
o  ASD diagnosis from a community provider.
•  The remaining 18% 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 role do schools play in the identification of children with ASD?
•  A greater percentage of children were identified
Health-Only Sites
with ASD when combining all ADDM Network
sites that reviewed both health and special
education records than when combining all
ADDM Network sites that reviewed only health
records.

•  ADDM Network data continue to highlight the
pivotal role schools play in evaluating and
serving children with ASD.

= 1 in 93 (or 1.1%)
Health and Special Education Sites

= 1 in 58 (or 1.7%)