The Centers for Disease Control released last week its biennial numbers of autism prevalence among young Americans, and the numbers continue to spike, continue to startle: According to the CDC, one in 68 children in 11 surveyed U.S. communities has been identified with autism spectrum disorder.
That compares to one in 88 children diagnosed with autism when the numbers were last released, in 2012.
The estimates were based on information collected from the health and special education records of children who were eight years old and who lived in 2010 in certain areas of Alabama, Arizona, Arkansas, Colorado, Georgia, Maryland, Missouri, New Jersey, North Carolina, Utah, and Wisconsin.
CDC officials and an array of public health officials, as well as more than a few major media outlets, were quick to say the 29-percent increase did not necessarily mean the number of children with autism was actually increasing; rather, they said, it likely means that increased awarenesss of the disorder has led to more accurate and frequent diagnoses that were missed in the past.
However, other experts and autism advocates dispute that assessment. While an increasing number of diagnoses might explain some of the increase decades ago when autism numbers began to spiral, they say, autism – its causes, its behaviors – has been a hot-button, front-page issue for close to a decade now. To these critics, that means doctors were as aware six years and four years ago as they are today, and so the rising numbers translate into real increases in the disorder.
The one-in-68 number breaks down to 14.7 diagnoses per 1,000 eight-year-old children in the sampling regions, compared to previous estimates reported in 2012 (for 2008) of 11.3 per 1,000 eight year olds.
Compared to figures of a decade ago, the new estimates for 2010 are dramatic. While the new estimate is about 30 percent higher than the estimate for 2008 (one in 88), it is 60 percent higher than the estimate for 2006 (one in 110), and approximately 120 percent higher than the estimates for 2002 and 2000 (one in 150).
The number of children identified with ASD ranged from one in 175 children in Alabama to one in 45 children in New Jersey, the CDC stated.
To gather the numbers, CDC researchers reviewed records from community sources that educate, diagnose, treat and/or provide services to children with developmental disabilities, the agency states. The criteria used to diagnose ASDs and the methods used to collect data have not changed over time, CDC also emphasizes.
Looking more closely at the new data, ASD is almost five times more common among boys than girls, as has been the case in the past. Approximately one in 42 boys versus one in 189 girls are on the spectrum.
In addition, white children are more likely to have ASD than black or Hispanic children. About one in 63 white children were diagnosed with ASD, the CDC stated, compared with one in 81 black children and one in 93 Hispanic children.
The disorder is spread across various ranges of intellectual ability, the CDC reported.
“Levels of intellectual ability vary greatly among children with autism, ranging from severe intellectual challenges to average or above average intellectual ability,” the report stated. “The study found that almost half of children identified with ASD have average or above average intellectual ability (an IQ above 85) compared to a third of children a decade ago.”
Of the diagnosed children, the agency reported, about 80 percent either received special education services for autism at school or had an ASD diagnosis from a clinician. The remaining 20 percent had symptoms of ASD documented in their records but had not yet been classified as having ASD by a community professional in a school or clinic.
In Wisconsin, the numbers departed from the national estimate. Ten counties in southern Wisconsin, including Milwaukee, compose one of the CDC’s 11 reporting “communities.”
In the Wisconsin survey, one in 108 children (or 9.3 per 1,000 8 year olds) was identified with ASD. Among boys, the rate was one in 65; for girls, it was one in 323 girls.
The racial breakdown was one in 95 for whites; one in 217 for blacks; one in 179 for Hispanics.
The Wisconsin tracking area included the counties of Dane, Green, Jefferson, Kenosha, Milwaukee, Ozaukee, Racine, Rock, Walworth, and Waukesha. In all, 35,623 eight-year-old children were tracked, of which 62 percent were white; 18 percent, black; 16 percent, Hispanic; and 4 percent, Asian or Pacific Islander.
Why the rise
It doesn’t dominate the headlines the way it did several years ago, but the debate about why the numbers continue to rise so dramatically continues to rage.
CDC officials continue to point to better diagnosis. Even now, agency officials say, the report shows most children are diagnosed after age four, even though ASD can be diagnosed as early as age two. Less than half of children identified with ASD, or 44 percent, were evaluated for developmental concerns by the time they were three years old.
Even so, CDC officials admitted they were uncertain about the causes.
“We don’t know what is causing this increase,” the CDC stated in its announcement. “Some of it may be due to the way children are identified, diagnosed, and served in their local communities, but exactly how much is unknown.”
Others, including the president of one of the nation’s largest advocacy groups, Autism Speaks, said the numbers represent a public-health crisis.
“Behind each of these numbers is a person living with autism,” Autism Speaks president Liz Feld said. “Autism is a pressing public-health crisis that must be prioritized at the national level. We need a comprehensive strategy that includes the research community, policymakers, educators, and caregivers coming together to address our community’s needs across the lifespan.”
Autism Speaks chief science officer Rob Ring also reacted to the numbers, saying diagnosis alone could not explain the increase.
“Some but not all of the increase may be due to increased awareness and diagnosis,” Ring said. “But much of the increase remains unexplained. Science has begun to identify some of the factors that increase or decrease the chances that a child will develop autism. For example, some studies suggest that increasing parental age is a contributor. But again, this doesn’t come close to explaining the dramatic increase.”
What doesn’t need explaining is the magnitude of the problem. Whether it’s just better diagnosis and or an actual increase, the fact is, among the CDC sample of the nation’s eight year olds, almost 1.5 percent of the nation’s children are on the spectrum, and that rises to 2.4 percent for boys.
Richard Moore may be reached at email@example.com.