March 20, 2013
CDC Revises Autism Estimate Up To 1 In 50 Children
Alan McStravick for redOrbit.com — Your Universe Online
Every morning and early afternoon, our communities are crisscrossed by large yellow buses ferrying our youth to and from school. A new survey commissioned by the Centers for Disease Control and Prevention (CDC) claims at least one child on each of those buses has a condition linked to the autism spectrum disorder. Nationally, this would mean up to one million children suffer from some form of autism.
The numbers presented in this survey, obtained through telephone interviews with 96,000 US households, shows a dramatic increase in the prevalence of autism over a similar study released just five years ago. In 2008, it was estimated 1 in 88 children suffered from the condition. This latest study sees that number jump to one in every 50 school aged children having been diagnosed with a form of autism.
The method of the study, when compared to the 2008 survey, is not without its controversy. This is because less than a quarter of the parents contacted by phone agreed to answer questions. Furthermore, it is believed parents of autistic children would have been far more likely to take the time to participate in the study than parents whose children did not suffer from autism spectrum disorder.
Even still, CDC officials claim they believe this latest survey provides a valid snapshot of how many families are affected by autism in the United States.
"This estimate was a bit surprising," said Stephen Blumberg, a senior scientist at the CDC's National Center for Health Statistics and lead author of the report. "There may be more children with autism spectrum disorder than previously thought."
According to associate director for Public Health Research and Scientific Review at Autism Speaks, Michael Rosanoff, “This study added to the evidence suggesting we are underestimating the prevalence of autism in the United States.” Rosanoff contends this study, while showing an increased prevalence over the 2008 study, is probably missing the mark, as well. “It´s probably much higher,” he said.
Experts don´t believe the increase is due to environmental factors, but rather because the medical community is improving their ability to diagnose the condition in children who might not have received an autism diagnosis previously, according to Blumberg. He says this is particularly true with regard to diagnosis in older children.
This trend has been noted in clinics across the nation. According to Dr. Roula Choueiri, a neurodevelopmental pediatrician with Tufts Medical Center in Boston, diagnosis of children over age eight has been on the increase over the past few years. She claims these children “tend to be the mild ones, who may have had some speech delays, some social difficulties.” However, as school becomes more demanding and their social situations become more complex, they experience an increase in problems associated with autism spectrum disorder.
Additionally, this latest survey shows boys were more than four times more likely to be diagnosed with autism than girls. This, according to Blumberg, follows the historical trend of the condition.
"For the most part, the increase in the prevalence is largely due to an increase in reported autism spectrum disorder for boys," he said.
The survey team noted there were no other factors, such as survey bias, that could explain the increase. Most of the children who were diagnosed with autism spectrum disorder were diagnosed since the 2008 survey.
"By ruling out other explanations and noting the increase in recent diagnoses, that suggests to us that improved ascertainment -- recognizing children who were previously unrecognized as having autism spectrum disorder -- is the reason," Blumberg said.
Experts claim it is important to note the 2008 survey was considered far more rigorous than the survey compiled for this latest report. The previous survey examined both medical and school records rather than relying on parental telephone survey reporting.
Of course, autism had been viewed through the narrow prism of children who suffered severe language, intellectual and social impairments along with unusual, repetitious behaviors. The definition has, of late, been expanded to now include milder, related conditions.
It is due to the broadened definition of autism, according to Blumberg, that many of the newly diagnosed children have popped up on the radar.
"It would certainly make sense that those with unrecognized autism spectrum disorder may have symptoms that are milder than children who have been diagnosed earlier," he said.
Rosanoff and the team at Autism Speaks agree with Blumberg´s contention that diagnoses of milder forms of autism have seen an increase in recent years.
"What we are seeing is that children who have not been diagnosed in the past are now being diagnosed," he said. "That is likely due to doctors and other health care providers being better at recognizing the more milder symptoms of autism and being able to diagnose those."
The challenge for the medical community is evident when it comes to pronouncing a diagnosis of autism. As there are no blood or biologic tests for the condition, diagnosis is far from an exact science. Medical professionals must, in order to arrive at their diagnosis, observe and make judgments about a child´s behavior, instead.
These behaviors often include difficulty with basic social skills. A student that has limited or dysfunctional social skills will often struggle in their interactions with others in a classroom setting and other social situations, Rosanoff said.
Rosanoff claims diagnosis, especially for those with milder forms of autism spectrum disorder, is vitally important because, while they may be doing well in the classroom, they could benefit from help with their autism.
"With appropriate diagnosis and access to services, a child with autism can improve in the way they function and how they are able to be successful in life," he said.
From a public health perspective, more accurate data is hugely important. This is because government officials, when deciding how to disburse limited public health funds, look at just how common an illness or disorder is.
Recognition of the increased prevalence of this condition can only be met with relief by parents of autistic children. Not only are their children less stigmatized, but the more common nature of the condition means public funding into research and awareness will likely increase, as well.