Autism Prevalence Rises in Communities Monitored by CDC

One in 54 8-year-old children have been identified with autism, according to an analysis of 2016 data published today in CDC’s Morbidity and Mortality Weekly Report (MMWR) Surveillance Summary.

This is higher than the previous estimate from 2014 data that found a 1 in 59 prevalence among 8-year-olds. The data come from 11 U.S. communities in CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network. Data from 2016 also show that more children are being evaluated and identified with autism at younger ages. The latest findings draw on data from two separate reports on both eight-year-old and four-year-old children.

“Some of the increase in autism prevalence might be due to the way children are identified, diagnosed, and receiving services in their communities,” said Stuart Shapira, M.D., Ph.D., associate director for science at CDC’s National Center on Birth Defects and Developmental Disabilities. “The increase may also reflect reductions in racial differences in identification of autism, as this is the first ADDM Network report to identify black 8-year-olds with autism as having the same rates as white children.

Racial gap reduced but differences remain

Despite improvements in autism identification among black children, the analysis shows differences with other groups continue. Hispanic children are identified with autism at lower rates than black or white children. Also, black and Hispanic children identified with autism received evaluations at older ages than white children. This means black and Hispanic children with autism who do not have intellectual disability might not be identified at the same rates as white children.

Gender differences

Boys were more than four times as likely to be identified with autism as girls. However, girls identified with autism were more likely to have intellectual disability than boys (39% of girls vs. 32% of boys).

Geographic differences in autism prevalence

Autism prevalence in the 11 communities varied widely, from 1.3% in Colorado to 3.1% in New Jersey. This could be due to how autism is being diagnosed and documented. Some communities have a higher concentration of services for children with autism and their families. Also, some communities can review both health and educational records of children, which can lead to more children identified with autism.

Improvements in early identification of autism

A separate report looking at 4-year-old children finds substantial improvements have been made in the number of children who had their first developmental screening by the age of 36 months. According to the report, 84% of 4-year-olds had received a first developmental screening by 36 months of age compared to 74% in the previous report with 2014 data. This is important because the earlier that children are identified with autism, the sooner they can be connected to services that can improve outcomes and lead to a better quality of life.

ADDM Network

CDC’s ADDM Network is a tracking system that provides estimates of the prevalence and characteristics of autism among more than 300,000 8-year-old children in 11 communities in Arizona, Arkansas, Colorado, Georgia, Maryland, Minnesota, Missouri, New Jersey, North Carolina, Tennessee, and Wisconsin. Data on 4-year-old children come from the Early ADDM Network, which is a subset of communities in Arizona, Colorado, Missouri, New Jersey, North Carolina, and Wisconsin.

The ADDM Network is the largest population-based program to monitor autism and the only autism tracking system that examines both health and education records. Because ADDM does not provide a representative sample of the entire United States, the combined prevalence estimates presented in today’s analysis cannot be generalized to all children aged 8 years in the United States.

What can parents do?

CDC’s Learn the Signs. Act Early program provides parents, childcare professionals, and healthcare providers with free resources, in English and Spanish, to monitor children’s development. The program offers parent-friendly, research-based milestone checklists for children as young as 2 months of age. CDC’s Milestone Tracker Mobile App can help parents track their child’s development and share the information with their healthcare providers. For more information visit www.cdc.gov/ActEarly.

CDC’s National Center on Birth Defects and Developmental Disabilities is celebrating 20 years of saving babies, helping children, protecting people, and improving health. For more information about our work visit https://www.cdc.gov/ncbddd/index.html.

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U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

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