CDC's Reported Spike in Autism Rates: A Deeper Look
When the Centers for Disease Control and Prevention (CDC) on March 27 released the findings of its study of autism spectrum disorder (ASD), medical and nonmedical media outlets alike jumped on the story, reporting it under breathless headlines.
"Autism rates jump again, affecting 1 in 68 children" (USA Today), "Autism diagnoses surge by 30 percent in kids, CDC reports" (NBC News), and "US autism rate surges, CDC reports" (Washington Post) were among the least shrill headlines in the lay media. And medical media outlets chimed in, as well—"Autism rates jump 30%, CDC reports" ran atop Medscape Medical News's coverage.
But those attention-grabbing headlines offer only part of the story—and what's more, they don't accurately characterize the data.
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While the new data are a reason for concern, the CDC cautions readers to maintain perspective in its coverage of the study at its Web site.
The study data, from the Autism and Developmental Disabilities Monitoring (ADDM) Network and published in Morbidity and Mortality Weekly Report,1 do indeed show that the estimated number of children identified with ASD continues to rise.
But the CDC's Web article, "10 Things to Know About New Autism Data," notes that the ASD estimates are based on the health and education records of children who were 8 years old and lived in areas of Alabama, Arizona, Arkansas, Colorado, Georgia, Maryland, Missouri, New Jersey, North Carolina, Utah, and Wisconsin in 2010. "About 1 in 68 children (or 14.7 per 1,000 8 year olds) were identified with ASD," item No. 1 of 10 says. "It is important to remember that this estimate is based on 8-year-old children living in 11 communities.
"It does not represent the entire population of children in the United States," the CDC article says—despite that many media reports and headlines erroneously suggested that it did apply to all American children.
The new estimate is 30% higher than 2008's (1 in 88), 60% higher than 2006's (1 in 110), and 120% higher than estimates from 2002 and 2000 (1 in 150).
"We don't know what is causing this increase. 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," the CDC site says. Moreover, the number of children identified with ASD varied widely by community, from 1 in 175 children in areas of Alabama to 1 in 45 children in areas of New Jersey.
The agency outlines other demographic information about the children in the study, including IQ, sex, race and ethnicity, developmental level, and age at ASD diagnosis.
These new data, the agency says, can be used to promote early identification, plan for training and service needs, guide research, and inform policy so that children with ASD and their families get the help they need.
"However, there remains an urgent need to continue the search for answers and provide help to people living with ASD," the CDC concludes, adding that the data "directs the focus on what we know now and what else we need to know to further characterize and address the needs of children with ASD and their families."
—Michael Gerchufsky
Reference:
1. Prevalence of autism spectrum disorder among children aged 8 years — autism and developmental disabilities monitoring network, 11 sites, United States, 2010. MMWR CDC Surveill Summ. 2014;63(SS02):1-21.