What’s Behind All Those CDC Numbers?


The Center for Engaging Autism tries to add insight to the news headlines about autism because families are vigilant in their quest to understand everything about ASD. Recently the US Center for Disease Control and Prevention released new numbers regarding the prevalence of autism. Prevalence is a statistic of the portion of people found to have a condition at a given time. It differs from the incidence, which is the rate at which new cases occur. The prevalence number of 1 in 50 for ASD made headlines. This is a rise from the CDC report of 1 in 88 in 2012. It sounds like an epidemic and it’s easy to stop at alarm. But, to understand the numbers we need to look at the CDC report to understand what they actually mean.

The CDC’s information came from parent reports, acquired by random telephone surveys. Parents answered questions about the ASD diagnosis, severity, and the age and year the child was diagnosed. This information was gathered in 2011 and 2012 from 65,556 children. From 2007 to 2013, parent-reported autism prevalence increased significantly in all of the age groups (6-17 range). However, many of the children were diagnosed after age seven and were more likely to be rated as having “mild” ASD.

The authors of these findings suggest that the increase in prevalence may have resulted from improved ascertainment of ASD by doctors and other health care professionals, especially when the symptoms were mild. Changes in determining ASD could occur because of changes in ASD awareness among parents or health care professionals, increased access to diagnostic services, changes in how screening tests or diagnostic criteria are used, or increased special education placements in the community.

In Minnesota the prevalence has been rising for two decades. This is evident in the special education statistics gathered by the Minnesota Department of Education. According to the Minnesota Annual Report of Special Education Performance, the K – 12 students in placement for ASD services were 9887 in 2007 and 13091 in 2010. These rising numbers fit with the CDC report. They definitely reflect both awareness by parents and special education placements. It is interesting that in looking at the numbers for toddlers ages three to five, we see growth from 2007 -2009 at 14.32%. However, there was a decrease in placements in 2010.

One would have to wonder if there was a change in how screening tests were used for special education placements. In keeping with the CDC report, the special education numbers suggest that many students are still being identified for special education after age five. Or could it be that some toddlers with ASD are being served outside of the public schools?

It is always important to look beyond the headlines to increase understanding of autism and the services in our community. Our children are more than statistics on the evening news. Information gives us power that can be used shape their lives.

Author: Editorial Team

A select group of our board members who have something to say, but want to say it together. We also use this byline for those who wish to write anonymously.

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