A new report from the Centers for Disease Control and Prevention estimates that one in 50 school-aged children has an autism spectrum disorder. That’s a significant increase from 2008, when the CDC estimated that 1 in 88 children had the disorder.
The data for this report came from a study by the CDC’s National Center for Health Statistics, which surveyed more than 95,000 parents with children under 17 years old.
In an interview with the Associated Press, health officials said that this is not an indication that autism is occurring more often. Rather, the results suggest that doctors are diagnosing autism, especially milder cases, more frequently.
The CDC gathered this data by randomly phoning households identified as having children under the age of 17. Of the households called, less than a quarter of parents agreed to the survey, which researchers attributed to the study using both landlines and cell phones to reach parents.
Experts told the New York Times that results should be interpreted cautiously. Other surveys conducted by the CDC have shown different prevalence rates. From the Times article:
...A study released last year by the CDC’s Autism and Developmental Disabilities Monitoring Network looked directly at school behavioral assessments and clinical reports of children who were 8 years old in 2008 and applied a standard checklist of criteria for the diagnoses. While that study found a 78 percent increase in autism spectrum disorders from 2002 to 2008, it said the likelihood of a child receiving such a diagnosis was 1 in 88. Because the methodologies were so different, as well as the age range of the children themselves, it was difficult, experts said, to draw conclusions about prevalence or diagnoses, not least because clinicians themselves use different assessment tools. A diagnosis of an autism spectrum disorder can change as a child grows older.