Friday, March 28, 2014

Keep Calm and Think Critically: The CDC's 1 in 68 Autism Numbers

Shannon Des Roches Rosa

Yesterday the U.S. Centers for Disease Control and Prevention (CDC) held a media briefing to announce and discuss readjusted estimates for autism prevalence: 1 in 68 children. But what does that estimate actually mean? Well, that takes some critical analysis, digging, and sifting, which we'll walk you through, starting with the CDC's Dr. Colleen Boyle's opening statement:
"CDC estimates that one in 68 children has been identified with autism. This estimate is based on information collected from health and special education records of children who are eight years old and living in 11 communities in Alabama, Arizona, Arkansas, Colorado, Georgia, Maryland, Missouri, New Jersey, north Carolina, Utah, and Wisconsin in 2010. These data are from CDC-sponsored autism and developmental disabilities monitoring network. The new estimate exceeds previous overall estimates, roughly it’s 30 percent higher than our last estimate of one in 88 children. To better understand the why, there's an urgent need to do more research. There's also an urgent need to put these findings to work for children and families. More is understood about autism than ever before, but these numbers are an important reminder of the need for answers and to use CDC's data to help children now."
Unfortunately, many news outlets seemed to stop there, which is why you've probably seen sensationalistic headlines such as "Why Did Autism Surge 30%?" and "CDC Confirms Dramatic Increase in Autism Rates." These proclamations completely ignore the CDC's Dr. Marshalyn Yeargin-Allsopp's comments, later in the briefing, that essentially autistic people have always been here -- the CDC is just getting better at identifying them; plus the CDC's understanding of just who qualifies as autistic has changed over time:
"I would just like to add that we recognize now that autism is a spectrum, so I think in the past we thought of children as being severely affected, meaning children with intellectual disability, children who were nonverbal, children with a host of co-occurring conditions, that was the picture of autism, I think, about ten years ago. Our understanding has evolved to the point that we understand now that there are children with higher IQs and children who perhaps are even not receiving special education services. So our understanding of autism has changed over time, and I think that our numbers may be reflective of some of that, as well." 
The 1 in 68 estimate is not surprising. The criteria for autism diagnoses have not just changed over time but changed to be more inclusive over time (Asperger's, added to the DSM in 1994, was folded into Autism Spectrum Disorders in 2013). Anthropologist Roy Richard Grinker studied autism rates in Korea in 2011, and concluded that a more realistic autism prevalence was 1 in 38. This means that the CDC's 2012 estimate of 1 in 88 was already a lowball. As are the new numbers, most likely.

But, again, what do the numbers mean? Ideally, better identification and better estimation of numbers means better identification and estimation of needs and supports. The CDC was also clear that they had identified disparities in exactly who gets identified, who gets overlooked, and why. From KQED's California Report/State of Health writer Rachel Dornhelm:
"...the prevalence seems to vary in different communities and among children of different races. The CDC found white children are far more likely to be identified with autism, even though scientists don’t believe the rates are truly different between whites, Hispanics or blacks. That means that the discrepancy lies in the diagnosis and services available in different communities."
TPGA science editor Emily Willingham elaborated on the racial and cultural factors affecting diagnoses, while reemphasizing the CDC's awareness of under diagnosis, at Pediatrics:
"From the data, it looks like a lot of sociocultural factors enter into the values. Given the huge variability from site to site and the ethnic differences, recognition and service availability are probably factors. Dr. Boyle referred repeatedly to the evolution of our understanding of autism and used the large percentage of children included in these values who have average to above-average intelligence as an example of that. Unlike numbers from a decade ago, these values include children who previously might not have been recognized as autistic." 
The under diagnosis is not just limited to racial and geographic factors. Julia Bascom of The Autistic Self-Advocacy Network (ASAN) noted the problematics of the CDC's not including autistic people over age 21:
"The lack of any data on adults represents a serious gap in CDC's efforts. When the United Kingdom conducted an adult prevalence study, it found the same rate of autism in adults as children, helping to debunk public hysteria over a so-called 'autism epidemic'."
In the same statement, ASAN's Ari Ne'eman confirmed that the increased prevalence rate should reinforce evidence-based expectations rather than cause alarm. ASAN also asserted that "considerable efforts are still needed to make diagnosis and services available to all."

To summarize, primary takeaways from the CDC report are:
  1. The CDC is getting better at identifying the autistic people who have always been here
  2. Better estimates of autism prevalence will ideally lead to better supports and services
  3. There is still much work to do, especially in under served communities and ethnic groups
The simplicity of these takeaways was lost on many, especially "autism epidemic"-focused organizations, many of whom have been quoted in subsequent articles as legitimate autism resources. Which really needs to stop happening.

 But while it is distressing to read articles incorporating opinions from groups whose mission is to eradicate rather than support autistic people like my son, I realize that not all readers or reporters know how to evaluate autism resources for trustworthiness. So, with the CDC's report in mind and April's Autism Awareness stampede fast approaching, I recommend reading and sharing TPGA's own guidelines on identifying autism pseudoscience, and the article from Ken Riebel of Autism News Beat To reporters on the eve of Autism Awareness Month. And heed Ken's advice:
"Keep your stories simple and focused. Unless you are familiar with the autism news beat, the more you venture into the weeds, the more likely you are to leave your readers with the wrong impression."
Any questions?