Study: 1 in 40 children have autism spectrum disorder

WASHINGTON – According to a study published Monday in the journal Pediatrics, one in 40 children would be suffering from an autism spectrum disorder in an American parent.

In other words, the condition has been reported in 2.5% of children, accounting for about 1.5 million children aged 3 to 17 years old.

A report published this year by the US Centers for Disease Control and Prevention estimated the prevalence of one in 59 children, or about 1.7%, based on 2014 data.

"The prevalence is not growing as fast, although the CDC data suggests that it continues to grow," said Thomas Frazier, chief scientist of the advocacy organization Autism Speaks, in a statement. He was not involved in the new report.

"What is happening is that these studies use slightly more liberal and inclusive methods than the CDC methods," said Frazier, adding that he preferred the CDC figures but included "that". they are probably a bit conservative ".

The new study is based on the 2016 National Survey of Children's Health, conducted by the US Census Bureau, which has collected information from parents of more than 50,000 children under 17 years of age. To be included in the estimate, parents should have reported that their child has already been diagnosed with Autism Spectrum Disorder and that he is currently suffering from the disease.

The new figures were also slightly lower than those of the National Health Interview Survey conducted in 2017. It estimated that 2.76% of children had already received such a diagnosis, which the authors of the new note report have a broader definition.

The fact that the new study is based on parental statements – which are not validated by health and education records, as in the CDC report – may be a limitation despite the breadth of research, according to the authors.

Frazier said the figure of 1 in 40 is "generally consistent with previous parent surveys and other direct prevalence studies in which researchers are directly looking for autism and trying to identify it." ".

The parents of the new study also reported more difficulties in getting the health care their children need, compared to those with Down syndrome or other behavioral disorders, such as anxiety disorder. hyperactivity with deficit of attention.

"Although we have seen progress in recent years, this confirms what we know about our parents – the fact that many children face unacceptable delays in diagnostic evaluation, even after parents, teachers or other educators have recognized the signs of autism, "said Frazier.

In the new study, more than one-quarter of children with autism spectrum disorders were taking medications to treat the symptoms of the disease, and nearly two-thirds received "behavioral treatments" in the past year, according to the report. study.

It also found a higher prevalence of autism spectrum disorders among certain groups such as boys, children of single mothers, and households living below the federal poverty line, compared to those at least four times higher than this group. income threshold.

The differences between the figures in the new study and those in the CDC study could be explained by the years they were conducted, the age of the children studied, and their place of residence, according to the new study.

The CDC report was based on data collected in 11 communities across the country but was not necessarily representative at the national level, according to Daisy Christensen, co-author of this report, who is responsible for surveillance within the sector. developmental disorders of the National Center for Birth Defects and CDC Developmental Disorders. .

"Parents know their children best," said CNN Christensen, who was not involved in the new report. "We want to encourage parents to become aware of their child's development, to know the milestones reached by children."

Autistic Spectrum Disorders, a lifelong developmental disability, are characterized by communication and social interaction problems with repetitive behavioral patterns.

The authors note that it is difficult to compare the new report with previous versions due to updates on how the survey collected its data and the wording of the questions.

"We can not say what proportion was explained by the changes in the internal investigation rather than by external factors," the authors wrote.

However, the report comes as the estimated prevalence of this disorder has been increasing for decades.

"In the 1980s and 1990s, the diagnostic criteria were expanded to include more children," said Christensen, "so I think it's definitely a possibility for the increase we've seen."

In the past, more than half of the children identified with autism also had an intellectual disability and now it's about a third, she says. "And it's really consistent with identifying children who may be outside the spectrum."

The authors of the new study also note that universal screening recommendations made in the 2000s may have led to an increase in prevalence among younger children, for example.

"Because there is no biological marker, [autism spectrum disorder] is a particularly difficult condition to follow, "note the authors.

But understanding how common it is is for health experts to distribute resources and provide families with the help they need, according to Frazier.

"Having prevalence estimates – even if there are variations – helps us advocate for better screening, diagnosis, interventions and support," he said. .