Sparking strong reaction from doctors and child development experts, an influential task force says there's "insufficient evidence" to argue definitely that the benefits of screening all young children for autism outweigh the harms.
"There's not enough evidence for us to recommend for or against screening in children for autism under 30 months," said David Grossman, vice chair of the U.S. Preventive Services Task Force and a Seattle pediatrician. "Clinicians need to make a judgment on their own about whether to screen. There is no right answer on that."
The findings, which apply to children between the ages of 18 months and 30 months who haven't exhibited any signs of the disorder, were published Tuesday in JAMA.
But some health professionals worry the position could result in pediatricians missing opportunities for early intervention, and could exacerbate disparities in treating autism.
Autism spectrum disorder, or ASD, is a developmental disability that causes social, communication and behavioral challenges, and it appears to be on the rise. One in 45 children were diagnosed with the disorder in 2014 and 1 in 68 in 2010 up from 1 in 150 in 2000.
According to the Centers for Disease Control and Prevention, parents of children with ASD often notice developmental problems before the child's first birthday. Children often show signs of differences in social, communication and fine motor skills as early as six months.
"We know from a lot of research that the earlier you can intervene with any developmental problem -- including autism -- the better off the child is," said Benard Dreyer, president of the American Academy of Pediatrics and a practicing pediatrician in New York. Though much is unknown, "what we do know is that screening works. Early intervention is good."
The task force members say they don't oppose screening, which typically involves a checklist of questions for parents about their child's behavior. In fact, it found "adequate evidence" that screening works in identifying autism in children in the 18-to-30-month age group. Grossman also noted that the risks of screening appear to be low.
Rather, the report says, without large, controlled studies, it's hard to say whether those assessments would help to identify children who might otherwise fall through the cracks -- leading to their diagnosis and helping them to get treatment that works.
The task force urges more research, calling for a larger study that measures how treatment affects clinical outcomes for children of varying ages who screened positively for ASD. They also caution that "policy and coverage decisions [should] involve considerations in addition to the evidence of clinical benefits and harms."
However, the American Academy of Pediatrics recommends a very different course, instead having practice guidelines in place since 2007 saying that testing every child for autism should be routine. Some pediatrics experts say these guidelines carry enough weight that, regardless of the task force's recommendations, the screening will be covered by most health insurance. For instance, it is deemed a preventive health service that, under the 2010 health reform, is covered by marketplace plans.
Studies show screenings are accurate. And separate research shows treating patients earlier for autism can help -- though there is some debate on how rigorous those studies are, said Michael Silverstein, an associate professor of pediatrics at Boston University School of Medicine. For instance, some had smaller sample sizes, or weren't randomized.
But these findings in isolation are not enough, said Silverstein, who co-authored an op-ed in JAMA analyzing the task force's recommendation. It doesn't necessarily prove screenings lead to interventions that improve a child's health, he said.
But others dispute this point.
"The scientific community has been unequivocal of their support for universal screening for toddlers for autism, regardless of risk status," said Alycia Halladay, chief science officer at the Autism Science Foundation, a New York-based nonprofit that promotes autism research. Halladay is not affiliated with the task force.
The task force's expectation, she said, is excessive. Research indicates screenings are effective in diagnosis. Early diagnosis leads to earlier interventions, which are more likely to have an impact, since children's brains are more malleable at that point, she added. That is reason enough to favor universal screening.
Screening advocates also point to another level of concern.
If pediatricians don't test all their patients, some said, that could make it even easier to miss cases of early autism, especially with children who are already more likely to go untreated.
Doctors could view the guidelines as reason not to screen children unless they clearly present symptoms, Halladay said. But wellness visits can be 10 minutes, and since the disorder's symptoms vary, they can be easily overlooked, she added.
Meanwhile, children are already more likely to be diagnosed early and treated if they are white or from middle- to high-income families, research has found. If the responsibility falls on families and pediatricians to notice symptoms and choose screenings, that disparity could worsen.
"The family with a lot of resources that has a strong educational background ... is going to raise concerns earlier and is going to push for a referral," said Jeremy Veenstra-VanderWeele, an associate professor of psychiatry at Columbia University. "Whereas the family without those resources won't necessarily push, or be in a position to push in the same way."
Veenstra-VanderWeele wrote an editorial in JAMA Psychiatry criticizing the task force's approach.
Doctors should consider the patients they serve, Grossman said. If parents are less likely to recognize symptoms, or if families are generally low-income, those doctors can perform screenings more often than not.
But it's premature, he said, to worry unscreened patients will go neglected. That assumes early screenings definitively do lead to patients getting effective treatment -- something Grossman argued remains unclear.
The findings are a call for research to better understand how much early treatment helps compared to later, said Craig Powell, an associate professor of neurology at the University of Texas Southwestern Medical Center. He wrote an op-ed in JAMA Neurology assessing the report.
The task force sends the U.S. Congress an annual report highlighting areas that deserve more research funding, Grossman said. He expects to highlight autism as among them.
There, the AAP agrees, Dreyer said.
"We applaud the call for more research," he said. "But in the interim, until we get more evidence, I would say we need to screen more kids, and we need to get them into services."
The U.S. Preventive Services Task Force is a volunteer panel of medical experts that makes recommendations about clinical preventive services. It's funded by the federal Agency for Healthcare Research and Quality. It is the same body that sparked controversy in recent years with recommendations that most women need fewer breast cancer screenings.