CDC prevalence estimates for autism remain at 1 in 68
This week we’ve had the opportunity to see the latest reports from the CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network. The ADDM is a surveillance network focused on following the prevalence of ASD. With the establishment of this network, we’ve been able to actually look at the prevalence rate of autism by estimating the rate from 8-year old children in 11 states across the U.S using the same approach each year. What is important about this approach is that prior to the establishment of this network in 2007 (using data from 2002) we were comparing prevalence estimates using different methodologies. We were essentially comparing apples to oranges, which made it difficult to draw conclusions about the rate of autism. With this network we’re able to compare apples to apples.
The way the ADDM operates is through work completed in two phases. The first phase consists of screening and summarizing comprehensive evaluations that are conducted by professional providers in the community in 11 different states (WA was not one). The second phase then involves review of this evaluation information by trained clinicians who determine if the child meets diagnostic criteria for autism. The other interesting thing about this surveillance network is that other information about the children is collected, such as gender, race and ethnicity, and intellectual functioning.
The most recent report presents results from surveillance findings from the year 2012. The study highlights an overall prevalence of autism of 14.6 per 1,000 or 1 in 68 for children 8 years of age, which is the same rate reported by the ADDM in 2014.
They also replicated previous results indicating differences in identification as a function of race and ethnicity. They found that white children were more likely than black and Hispanic children to be identified with autism, and that these children were more likely to receive developmental evaluations later than white children. This difference in prevalence rates across racial/ethnic lines is not due to a difference in prevalence, but rather a result of decreased access to care and services. Additionally, just because the prevalence rates are the same as they were two years ago, this does not mean that we’ve answered the question about prevalence and can focus our attention elsewhere.
On the contrary, these findings highlight our continued need to develop supports and services to meet the needs of all children and families impacted by autism.
There are a couple of essential points that are important to consider about these findings. There is still a wide range of prevalence rates as a function of geographic region with some states having much higher prevalence rates than others. As such, the 8-year old children in these 11 states in the ADDM Network do not provide a representative sample of the entire country. As a result, the prevalence estimates presented do not necessarily generalize to all children (not even all 8-year old children) in the United States population.
However, these findings do highlight where we need to focus our attention: on meeting the needs and increasing access for minority children and on maintaining and increasing awareness of ASD for everyone.
Here is the link to the article.