A new U.S. government survey released on Wednesday seeking to assess the rate in which Autism is currently being diagnosed, has revealed that current rates of diagnosis are increasing significantly.
However, the study which finds that 1 in 50 U.S. children have Autism, as opposed to an earlier study which put Autism rates at 1 in 88 children, has one major confounding variable difference. The earlier study relied on medical records while this current survey relies on the the opinion of parents who believe their child has Autism.
According to this most recent estimate by the Centers for Disease Control and Prevention, the study was taken via phone survey of 95,000 parents who had an interest in being involved in the survey and likely felt their child had Autism whether they were officially diagnosed with Autism or not. Further, the parents willing to participate in the survey made up less than 25% of the parents contacted by the CDC.
Michael Rosanoff of Autism Speaks stands behind the validity of the survey released on Wednesday, claiming that prior Autism rates have been grossly underestimated.
According to the Kansas City Star, the prior study from 2008 showing a lower Autism rate also had some problems. That survey was limited to primarily 14 states and only examined the medical records of 8-year-olds (whom parents gave consent) specifically.
The process of diagnosing Autism is largely subjective, with doctors assessing behavior by way of qualitative impairment symptoms. The diagnosis relies on a snapshot of clinical observation but mostly relies on parental interviews.
MSNBC spoke with Stephen Blumberg of the National Center for Health Statistics, who published the survey in a report, and he suggested that the increase in diagnosis’ may come from an increased awareness of Autism and recognition of symptoms. Blumberg also suggests that children with mild symptoms may have an increased chance of being diagnosed with Autism as compared to a few years ago.