The newest estimates are based on data collected in 14 areas of the United States during 2008. These 14 communities comprised over eight percent of the United States population of 8-year-olds in 2008. Information was collected on children who were 8 years old because previous work has shown that, by this age, most children with ASDs have been identified for services.
Among the findings:
- A 23% increase since the last report in 2009. And, a 78% increase since the first report in 2007. Some of the increase is due to the way children are identified, diagnosed and served in their local communities, although exactly how much is due to these factors in unknown.
- ASDs are almost 5 times more common among boys (1 in 54) than among girls (1 in 252).
- More children are being diagnosed at earlier ages—a growing number of them by age 3. Still, most children are not diagnosed until after they reach age 4, even though early identification and intervention can help a child access services and learn new skills.