Saturday, August 8, 2015

Autism screening in asymptomatic children

Evidence of the merits of autism screening for asymptomatic children when no concerns have been raised by the parent or healthcare provider is insufficient to recommend either for or against such screening, according to a draft recommendation on the matter issued this week by the United States Preventive Services Task Force (USPSTF), but at least one major organization, the American Academy of Pediatrics (AAP), disagrees.

In addition to possible grades of A through D, recommending for or against a service or action, the USPSTF can settle on "I," indicating that current evidence is insufficient to assess the balance of benefits and harms of a service, as was decided in this case.

"We want to get the message out that an 'I' doesn't mean not to screen or that there is no evidence on the issue but just that evidence is inadequate in terms of screening asymptomatic children under the age of 3 whose parents have not expressed concerns," USPSTF Vice-Chair David Grossman, MD, MPH, a pediatrician in Seattle, Washington, told Medscape Medical News.

"Clinicians should use their clinical judgement and remain aware of signs and symptoms of autism, and certainly if parents begin to express concerns, that's a different story," he said.

The recommendation was based on a review of 17 unique published studies that met the USPSTF's criteria for review and 42 studies involving interventions.

The task force found no randomized trials that looked directly at the issue of the efficacy of autism spectrum disorder screening in children aged 3 years and younger in terms of improving core symptoms, cognitive and intellectual functioning, and other factors, such as communication skills or quality of life for the child and family.

"Most of the literature involves older children with more severe symptoms," Dr Grossman said. "We really would like to see more trials of younger children."...

Although evidence was insufficient to recommend screening with any particular tool, Dr Grossman noted that "we did agree that the evidence supports the [commonly used] M-CHAT [Modified Checklist for Autism in Toddlers]."

Newer revisions of the M-CHAT include the Modified Checklist for Autism in Toddlers With Follow-up and the Modified Checklist for Autism in Toddlers, Revised With Follow-up (MCHAT-R/F).
For the parent-rated MCHAT-R/F, a positive finding triggers a follow-up interview, and if the interview is positive, a full diagnostic workup for autism spectrum disorder is indicated.

The review represents the first time the USPSTF has taken up the issue of autism screening in asymptomatic children, which was prompted by a nomination that the panel felt met its criteria for consideration, Dr Grossman said...

In terms of medical society guidelines on the matter, the AAP's Bright Futures Guidelines do call for universal screening for autistic spectrum disorder in all children at ages 18 and 24 months, and the group issued a statement expressing its disagreement with the task force's conclusion.

"Because early identification and referral for appropriate intervention are critical to ensuring that children with autism have access to effective therapies, the AAP recommends all children be screened for ASD at ages 18 and 24 months, along with regular developmental surveillance," the AAP's president, Sandra G Hassink, MD, wrote in the statement.

"The draft recommendation statement on autism screening released Aug. 3 by the US Preventive Services Task Force runs counter to AAP guidelines," she writes.

"The AAP remains committed to its recommendation for the timely screening and identification of children who would benefit from early intervention and treatment."

Contrary to the task force's review, "research shows that early intervention can considerably improve children's long-term development and social behaviors," Dr Hassink writes.

With the recommendation for the use of autism screening at 18 and 24 months having been in the AAP's guidelines since 2007, the task force's draft recommendation was therefore not expected, said Susan E. Levy, MD, MPH, of the Division of Developmental and Behavioral Pediatrics at the Children's Hospital of Philadelphia and chair of the AAP's Autism Subcommittee.
"We were surprised and a little dismayed," she told Medscape Medical News. "I know the AAP and other groups are planning to give feedback during the public comment period with the hopes that the wording of this can be modified to prevent a negative outcome."...

Furthermore, the draft recommendation applies to children who are asymptomatic, but it is important to consider that not all parents may be able to identify symptoms, Dr Levy added.

"Parents who, for instance, have their first child may not be as aware of some of the subtle characteristics of autism or autism spectrum disorder, so they may not be able to identify the children as having problems, so that's another important reason for screening."
Neurologist Ann Tilton, MD, a professor of neurology and pediatrics and section chair of child neurology at Louisiana State Health Science Center in New Orleans, Louisiana, agreed, noting that in such cases, the burden is placed on the physician to identify potential symptoms.

"If parents don't recognize abnormalities, then it can come down to the degree of surveillance on the physician's part, and it may very often be difficult for the physician to spend enough time to truly observe the child," she told Medscape Medical News.

"So it makes sense that the pediatricians and the AAP are the ones recommending the higher level of screening."

1 comment:

  1. Few would dispute that children who are exhibiting signs or symptoms of autistic spectrum disorder should be referred and tested. It is when we talk about screening every child for autism that the debate becomes heated.

    Recently, the United States Preventive Services Task Force released its draft recommendation statement on the screening of young children for autism spectrum disorder. The task force decided that the current evidence was not enough to recommend widespread screening of children with no symptoms. This led many people to worry that the group was telling physicians not to screen.

    The American Academy of Pediatrics disagrees with the task force. For years, the academy has argued that all children should be screened at 18 and 24 months of age. Pediatricians tend to believe that identifying this problem early and getting children help leads to the most benefit. Moreover, they believe that without universal screening, autism may be missed and treatment delayed for some children, leading to worse outcomes...

    Whenever anyone is discussing a screening test, I usually have four questions, which I’ve adapted from David Sackett’s classic handbook on evidence-based medicine: (1) Is the condition prevalent and severe enough to warrant screening? (2) Do we have a cost-effective means to screen the general population? (3) Does early diagnosis make a difference (that is, do we have treatments available that are more successful when patients are diagnosed earlier?) And (4) Will an early diagnosis motivate people to use information gained from screening?...

    That leaves Question 3, which asks whether early intervention works for children with autism. There’s not much disagreement there, either. In its discussion of the effectiveness of early detection and treatment, the task force noted that 26 “good” and “fair” randomized controlled trials studied early intensive behavioral and developmental interventions. Three of four trials found that interventions improved cognitive scores, like the I.Q., 11 to 16 points. They also showed improvement in language skills. Twelve trials examining play- or interaction-based interventions showed significant improvements in measures of interactions with others.

    The task force’s quibble is that these interventions were performed in children already found to have autism spectrum disorder. They weren’t conducted in children whose positive screen led to diagnosis but who hadn’t yet been symptomatic enough to concern their parents or physicians without screening.

    In a perfect world, asking for a study specifically involving those children might be a reasonable request. In the real world, such a study is almost certainly not going to happen. At least, not anytime soon...

    The task force is trying to demand a high level of evidence before recommending a screening test be performed universally. But without the stamp of approval from the group, payment for screening is not mandated by the Affordable Care Act. And no studies satisfying the requirements of the task force are likely to be done soon. This means that less screening will be done, even though we know three things: Autism is prevalent, screening works, and early intervention seems to make a difference in those found to have the condition.
    Courtesy of a colleague