Routine screening for autism risks treating children like guinea pigs by exposing them to tests that haven't been sufficiently studied or proven to be effective, a new Canadian study warns.
In a report published in the journal Pediatrics on Monday, researchers from McMaster University reject the idea that screening for autism should be incorporated into regular practice at doctors' offices and that all children should be screened, even if they show no signs of the disorder.
"Up to now, the evidence is not supporting a screening program," said Jan Willem Gorter, a researcher at McMaster's CanChild Centre for Childhood Disability Research.
There is no proof screening programs work, Dr. Gorter said, and they could do more harm than good by classifying non-autistic children as having the condition, and vice-versa.
The blunt assessment flies in the face of growing support for early screening programs and a recommendation from the American Academy of Pediatrics that all children undergo routine testing for autism.
Many medical experts have voiced support in recent years for programs to help identify autism in children before they reach age 2. The idea is that the earlier the disease is detected, the earlier the child can start treatment.
The AAP published a report in 2007 urging that all children be screened twice before age 2. The organization recommends looking for specific signs, such as failure to make eye contact or use non-verbal communications like waving or gesturing.
The recommendations sent shock waves through the research community and raised many questions about whether they should be adopted.
"We've really struggled with this," said Wendy Roberts, a developmental pediatrician at Holland Bloorview Kids Rehabilitation Hospital and the Hospital for Sick Children.
The problem is that while certain signs can point to autism, such as a delay in learning to speak, there are no hard-and-fast rules for diagnosing the condition in babies. Attempting to make an early diagnosis can result in false positives, which would cause significant grief for parents and cause children to undergo therapies they didn't need.
It's also very difficult, ethically, to study the potential benefits of autism screening programs, because that would require some children to be screened while others would go without.
On the other hand, Dr. Roberts said, there is a growing amount of compelling evidence that early diagnosis and treatment are key to improving outcomes for autistic children. "We have increasing evidence that the earlier you pick up red flags, even before you get a formal diagnosis for a certain group of kids, it can really make a difference in outcome."
Instead of setting up screening programs that may rely on untested methods, Dr. Roberts said, leading Canadian researchers are looking to train doctors and nurse-practitioners to ask parents questions in order to spot red flags. Work is continuing to determine the best methods for recognizing signs of the disorder early, she said.
Dr. Gorter said it does appear that screening programs can be effective. But at this point, the lack of evidence demonstrating how effective they are means they shouldn't be applied to all children. Instead, efforts should be focused on figuring out the best methods for early diagnosis.
"If there's no evidence, it doesn't mean [screening]doesn't work, but we have to find evidence supporting such a program," he said.