The reason for the rise is not known, and cannot be determined from the report. But the findings suggest that doctors and other healthcare professionals are getting better at identifying and diagnosing mild forms of autism, said study researcher Stephen Blumberg, of the Center for Disease Control and Prevention's National Center for Health Statistics, the organization the released the report.
Because the findings are based on parents' reports, and were not confirmed by a doctor or the patient's medical records, they might not be entirely accurate. However, previous estimates based on parental reports have generally matched those based on medical records, the researchers said.
The new findings are not directly comparable to a report released last year, which found that 1
in 88 children U.S. children has autism. That report was based on information collected in 2008 from 8-year old children living in 14 areas in the United States.
The new study is based on phone surveys of 96,000 parents in 2011 and 2012. Parents were asked if a doctor or health care professional had ever
diagnosed their child with an autism spectrum disorder.