Data from 14 states participating in a federal project to study autism-spectrum disorders show that about six of every 1,000 children had the developmental disabilities, the U.S. Centers for Disease Control and Prevention reported last week.
The findings, from the first and largest summary of data on the prevalence of the disorders in multiple communities in the United States, were based on reports on 8-year-olds, since by that time the majority of children with ASDs have been identified.
The findings translate to one in every 150 children in the communities studied having disorders such as autism, pervasive developmental disorder (not otherwise specified), or Asperger’s syndrome.
The study did not provide a national estimate for the prevalence of the disorders.
Previous estimates had indicated that between one in 500 children and one in 166 have an autism-spectrum disorder, federal health officials said.
Those developmental disabilities are defined by children’s impairments in social interaction and communication and by the presence of unusual behaviors or interests. They can be diagnosed as early as 18 months of age, the Atlanta-based CDC said, and most parents reported developmental concerns before age 3.
“Our estimates are becoming better and more consistent, though we can’t yet tell if there is a true increase in ASDs or if the changes are the result of our better studies,” CDC Director Dr. Julie Gerberding said in a statement. “We do know, however, that these disorders are affecting too many children.”
The study includes findings from six states in 2000 and 14 states in 2002.
A version of this article appeared in the February 14, 2007 edition of Education Week