In the largest study yet examining proposed changes to the autism diagnosis, researchers say far fewer people would be cut from the spectrum than previous studies have suggested.

Major changes to the autism diagnosis are expected in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, or DSM, slated for publication in May 2013. The proposal has brought widespread concern in the autism community after a study earlier this year suggested that a significant number of people currently diagnosed with autism may not qualify under the new definition.

Now, a new study suggests that those fears may be largely unwarranted. Researchers examined records for 4,453 children currently diagnosed with autism under the DSM-IV criteria to determine how they would fare under the proposed changes. They found that 91 percent of the kids would still qualify for an autism diagnosis, according to the study published Monday in The American Journal of Psychiatry.

“I know that parents worry, but I don’t believe there is any substantial reason to fear that children who need to be diagnosed with autism spectrum disorders, and provided with vital services, will not be included in the new criteria in this updated manual,” said Catherine Lord, the study’s senior investigator and the director of the Center for Autism and the Developing Brain at NewYork-Presbyterian Hospital’s Westchester campus.

Lord is also a member of the American Psychiatric Association panel responsible for the proposed changes.

Though the findings differ from a handful of other analyses, Lord said the latest study is the biggest and most rigorous to date. What’s more, she says it’s based on information on kids from three data sets that were all collected for different reasons.

The true test, however, will come when clinicians of varying pedigrees will be left to interpret the changes.

“What they report is impressive in scope and magnitude, but it is using meticulously characterized cases with what are probably very experienced clinicians,” Fred Volkmar, the Yale University researcher who led a similar study earlier this year with different findings, told The New York Times. “The problem is one of moving this to the real world outside of academic centers.”

Under the DSM proposal, autistic disorder, Asperger’s syndrome, childhood disintegrative disorder and pervasive developmental disorder, not otherwise specified would be folded under one umbrella diagnosis of “autism spectrum disorders,” with clinicians indicating a level of severity associated with an individual’s condition. To qualify for an autism diagnosis under the new criteria, a person would have to exhibit specific types of deficits in socialization and behavior.

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