New CDC Data: Autism May Be More Prevalent Than Previously Thought

In a February 8 press release, The Centers for Disease Control and Prevention (CDC) reported that about 1 out of every 150 children included in 2 nationwide surveys may have autism or a related condition - more than many researchers had estimated. The surveys, conducted in 2000 and 2002 with subjects from 6 and 14 communities respectively, are the largest of their kind to date.

The 2002 study looked at approximately 10 percent of eight-year-olds living in 14 states - Alabama, Arizona, Arkansas, Colorado, Georgia, Maryland, Missouri, New Jersey, North Carolina, Pennsylvania, South Carolina, Utah, West Virginia, and Wisconsin. Of these, an average of 6.6 per 1,000 eight-year-olds, or 2,685 total, showed signs of an autism spectrum disorder (ASD). Researchers examined descriptions of the children's developmental difficulties obtained from parents, teachers, and other adults.

A similar study was conducted in 2000 with approximately 4.5 percent of eight-year-olds from six states - Arizona, Georgia, Maryland, New Jersey, South Carolina, and West Virginia. An average of 6.7 per 1,000 children, or 1,252 children total showed signs of an ASD.

The data from both studies translates into an average ASD rate of about 1 in 150 children across these communities. The studies focused on eight-year-olds because research indicates that most children with an ASD are diagnosed by this age.

"It's important to note that these studies don't provide a national estimate, but that they do confirm that ASDs in the areas surveyed are more common in these communities studied than previously thought," said Dr. Marshalyn Yeargin-Allsopp, chief of CDC's autism program. "We need to continue efforts to monitor the prevalence of ASDs and to improve our understanding of these disorders. Good estimates of how many children in a community may have an ASD will also help school and health officials in their planning and intervention efforts."