New report shows slight uptick in autism prevalence

Inching up: With increasing awareness of autism, the prevalence of the condition continues to rise slightly. EyeEm / Getty Images

Source: [Spectrum, | April 26, 2018]

About 1 in 59 children in the United States has autism, according to data released today by the U.S. Centers for Disease Control and Prevention (CDC). Four times as many boys as girls have the condition, according to the report1.

The data are based on a 2014 survey of 325,483 children across 11 states. The data were collected by the CDC’s Autism and Developmental Disabilities Monitoring Network (ADDM).

These numbers show an increase of nearly 16 percent from the previous prevalence of 1 in 68 children. That estimate was based on data collected in 2012 and had a gender ratio of 4.5 to 1.

The trend from that analysis and another one in 2010 had suggested that autism prevalence in the U.S. was leveling off. Another CDC study published earlier this year also suggested that autism rates are no longer increasing.

The new findings buck this trend. But they do not necessarily mean the actual number of children with autism in the U.S. is rising, says Catherine Rice, director of the Emory Autism Center in Atlanta and principal investigator for the ADDM from 2001 to 2010.

“The current ADDM report seems to indicate that awareness of [autism] characteristics is broadening and this contributes to increases in [autism] prevalence overall,” Rice says.

For example, autism prevalence is consistently higher in white children than in black or Hispanic children — a pattern researchers attribute to disparities in access to medical care. This difference has been trending downward since 2002.

The 2012 analysis identified 20 percent more white children with autism than black children and 50 percent more than Hispanic children. In the new analysis, researchers identified 7 percent more white children with autism than black children, and 22 percent more than Hispanic children.

This suggests that the rise in prevalence may be the result, in part, of improved services for children who were previously missed.

“We have no reason to think there’s some biologic basis for a difference in [autism] prevalence among these populations,” says Deborah Christensen, team lead for surveillance in the CDC’s developmental disabilities branch. “So when we see those differences narrow, that is encouraging to us.”

Robust records:

The new survey focused on 8-year-olds, as most children are likely to have had a medical or school evaluation by that age.

Expert reviewers in the ADDM look for signs of autism in the medical records of children living in select counties and states across the U.S.

The reviewers may include children who show signs of autism, even if they do not have an official diagnosis. And they may choose to exclude children who are diagnosed with autism if their features do not meet criteria for autism as outlined in the “Diagnostic and Statistical Manual of Mental Disorders” (DSM).

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