According to the CDC, one in 68 children have an autism spectrum disorder, and about half are diagnosed after the age of 4 — an age that many researchers consider towards the end of an optimal intervention “window.” The most common screening tool is the M-CHAT, a 20-question form that parents fill out while awaiting a child’s well visit. Many questions have to do with child responsiveness, and it is understood that many will generate a false positive. In the case of a positive risk score, an M-CHAT follow-up is administered. While all those who screen positive on the follow-up may not be diagnosed with an autism spectrum disorder, they are at high risk of other developmental disorders and delays, therefore warranting further evaluation.
The panel concluded, however, that not enough evidence currently exists to assess the benefits and harms of screening for autism spectrum disorder in children.
“The USPSTF also found inadequate evidence on the efficacy of treatment of cases of ASD detected through screening. Treatment studies were generally very small, few were randomized trials, most included children who were older than would be identified through screening, and all were in clinically-referred rather than screen-detected patients,” the panel wrote.
Despite agreeing that screening methods do identify autism at young ages and that early intervention does lead to significant improvements in some children with autism, the panel highlighted the fact that there are few studies that evaluate the long-term outcomes of children identified with universal screening, compared to those with more severe symptoms.
“I don’t think that anyone is arguing that there isn’t limited data, but the reality is that a study to prove what’s worthwhile would be an extraordinarily complicated and expensive thing to do,” Catherine Lord, PhD, founding Director of the Center for Autism and the Developing Brain at New York-Presbyterian Hospital, told Neurology Advisor.
A study of the caliber that the panel refers to would involve putting together information from multiple studies focused on screening, screening to services, and services to outcomes, a standard that Lord says won’t be met.
“The AAP has worked very hard to try and get autism on the map of busy primary care pediatric providers who may find it difficult to be attuned to the kind of symptoms that involve autism. It’s very hard to have a screening instrument, and while it is not at a state of perfection, I think it’s an unfair criticism.”
The draft proposal is open for public comment now through August 31, 2015.