In The Politics of Autism, I discuss the likelihood that the increase in autism diagnoses and educational determinations at least partially the result of increased awareness and changes in diagnostic criteria
Michael D. Kogan and colleagues have an article at Pediatrics titled "The Prevalence of Parent-Reported Autism Spectrum Disorder Among US Children." The Abstract:
OBJECTIVES: To estimate the national prevalence of parent-reported autism spectrum disorder (ASD) diagnosis among US children aged 3 to 17 years as well as their treatment and health care experiences using the 2016 National Survey of Children’s Health (NSCH).
METHODS: The 2016 NSCH is a nationally representative survey of 50 212 children focused on the health and well-being of children aged 0 to 17 years. The NSCH collected parent-reported information on whether children ever received an ASD diagnosis by a care provider, current ASD status, health care use, access and challenges, and methods of treatment. We calculated weighted prevalence estimates of ASD, compared health care experiences of children with ASD to other children, and examined factors associated with increased likelihood of medication and behavioral treatment.
RESULTS: Parents of an estimated 1.5 million US children aged 3 to 17 years (2.50%) reported that their child had ever received an ASD diagnosis and currently had the condition. Children with parent-reported ASD diagnosis were more likely to have greater health care needs and difficulties accessing health care than children with other emotional or behavioral disorders (attention-deficit/hyperactivity disorder, anxiety, behavioral or conduct problems, depression, developmental delay, Down syndrome, intellectual disability, learning disability, Tourette syndrome) and children without these conditions. Of children with current ASD, 27% were taking medication for ASD-related symptoms, whereas 64% received behavioral treatments in the last 12 months, with variations by sociodemographic characteristics and co-occurring conditions.
CONCLUSIONS: The estimated prevalence of US children with a parent-reported ASD diagnosis is now 1 in 40, with rates of ASD-specific treatment usage varying by children’s sociodemographic and co-occurring conditions.
At AP, Lindsey Tanner has a very sensible report:
Various reports in recent years have suggested autism rates are rising slightly. Experts think that's mostly because of earlier diagnosis, an expanded definition and more awareness, but say they can't rule out a true increase caused by unknown factors.
How many American children have autism? The U.S. government answers that question at least three different ways and says the latest estimate — 1 in 40 kids — doesn't necessarily mean the numbers are rising.
Here's a rundown on the three surveys:
— The latest estimate is based on responses from about 43,000 parents of kids aged 3 to 17. They were asked if their child had ever been diagnosed with autism spectrum disorder, the formal name that encompasses mild to severe cases. The 2016 survey was internet-based; earlier ones were telephone surveys showing slightly higher rates but the researchers say the results aren't comparable,
The nationally representative survey suggests that about 1.5 million U.S. kids have autism — 2.5 percent or 1 in 40.
— The Centers for Disease Control and Prevent collects nationally representative information from in-person interviews. In 2016, it also asked parents of kids aged 3 to 17 about an ever-diagnosis of autism and came up with a rate slightly higher than in previous years but similar to the 1 in 40 estimate.
— The CDC also uses an 11-state tracking system. It's based on health and school records showing which kids meet criteria for autism, focusing on 8-year-olds because most cases are diagnosed by that age. A report from this network released in April, showed that 1 in 59 kids have autism although much higher rates were found in some places. This estimate is considered the most rigorous, but it's not nationally representative.