About one in 88 U.S. children has been diagnosed with autism or a related disorder by age eight, according to a CDC study released Thursday, the New York Times reports (Carey, New York Times, 3/29).
For the study, researchers analyzed school and medical records of 337,093 children who were age eight in 2008 (Begley, Reuters, 3/29).
The study found 11.3 cases of autism spectrum disorder per 1,000 children in 2008, a 23% increase over 2006 and 78% increase over 2002. On average, autistic children were diagnosed at age four (Brown, Washington Post, 3/29).
According to the study, boys are five times more likely to be diagnosed with autism spectrum disorders -- one in 54 boys compared with one in 252 girls (Reuters, 3/29).
Guessing the Reason Behind the Increase
Public health officials said the increase in cases could be related in part to more diagnoses among minority and younger children, according to the Wall Street Journal.
The outstanding question is whether there actually was an increase in incidence, not just in diagnoses (Wang, Wall Street Journal, 3/29).
CDC Director Thomas Frieden attributed the higher rates to improved awareness of the disorder and methods of diagnosis. "I think we can say it is possible that the increase is the result of better detection," Frieden said (Reuters, 3/29).