One in 31 eight-year-olds, and a fivefold gap between two sites

The Autism and Developmental Disabilities Monitoring Network is an active
surveillance programme estimating the prevalence and characteristics of autism
spectrum disorder among children aged 4 and 8 years. In 2022, sixteen
sites took part, across **Arizona, Arkansas, California, Georgia, Indiana,
Maryland, Minnesota, Missouri, New Jersey, Pennsylvania, Puerto Rico,
Tennessee, Texas (Austin and Laredo), Utah and Wisconsin.**

The headline, and the spread beneath it

**Among children aged 8 in 2022, ASD prevalence was 32.2 per 1,000 — one in
31 — across the sixteen sites.**

It ranged from 9.7 in Laredo, Texas to 53.1 in California.

More than a fivefold difference between two places in the same country,
measured the same way in the same year. Autism does not vary fivefold between
Texas and California; identification does. What this network measures is
partly the condition and partly the capacity of local services to recognise
and record it.

That is why the figure is reported by site rather than as one number, and why
"one in 31" should be read as an average of sixteen very different situations.

By sex and by group

ASD was 3.4 times as prevalent among boys (49.2) as among girls (14.3).

That ordering is a reversal of the historical pattern, in which autism was
identified most often in white children. Lower prevalence among white children
now suggests that identification in other groups has caught up and, in some
places, gone further.

Income

**No association between prevalence and neighbourhood median household income
at 11 sites. At five sites, higher prevalence was associated with lower
income.**

No consistent relationship, in either direction, across the network.

How a child was counted

A child was classified as having ASD if they had ever received **an ASD
diagnostic statement in a comprehensive developmental evaluation**, **autism
special education eligibility**, or an ASD diagnostic code (ICD-9 299 range,
or ICD-10 F84.0, F84.3, F84.5, F84.8 or F84.9).

Four-year-olds could also be classified as suspected ASD where an
evaluator had documented a suspicion without a diagnosis.

Every one of those routes runs through a service a child has to reach first —
which is the Laredo–California gap, stated as a method.

*Source: Shaw KA, Williams S, Patrick ME, et al. Prevalence and Early
Identification of Autism Spectrum Disorder Among Children Aged 4 and 8 Years —
Autism and Developmental Disabilities Monitoring Network, 16 Sites, United
States, 2022. MMWR Surveillance Summaries, Centers for Disease Control and
Prevention.*