A child with autism. Photo credit: CDC
One in 88 children in the US have a disorder on the autism spectrum (ASD), according to recently published report by the Center for Disease and Control (CDC) — a figure that represents a 23 percent increase since the last report, issued in 2009.
Disorders on the autism spectrum are a group of developmental disabilities that can cause significant social, communication and behavioural challenges in children. The increase in diagnoses of ASDs is, in part at least, due to better screening and diagnosis in the local communities; more children, for example, are being diagnosed with a disorder by the age of 3 than before. However, the CDC cannot quantify all factors that influence identification of children with autism and researchers still don’t know enough about what causes autism to say how much of the increase is due to etiologic factors versus better identification.
Jon Baio, an epidemiologist with the CDC’s National Center on Birth Defects and Developmental Disabilities and lead author of the report, said that the study’s estimates came from 14 sites within its US tracking network: Alabama, Arizona, Arkansas, Colorado, Florida, Georgia, Maryland, Missouri, New Jersey North Carolina, Pennsylvania, South Carolina, Utah and Wisconsin.
“Sites were selected through a competitive objective review process on their ability to conduct active, records-based surveillance of ASDs; these were not selected to be a nationally representative sample,” Baio explained via email. “However, these estimates are comparable to those from a nationally representative U.S surveys from the same time-period. If our tracking estimates and recent national surveys are applied to the US as whole, we’d estimate that more than 1 million children have autism.”
“We’d estimate that more than 1 million children have autism,” said Jon Baio, lead author of the CDC study.
The study was conducted in 2008, revealing a wider range of estimated prevalence that was identified in previous years, though the number of children identified with autism varied widely across the 14 sites, from 1 in 210 in Alabama to 1 in 47 in Utah. Over the 14 sites, researchers identified 11.3 per 1,000 8-year-old children as having an ASD. ASDs are almost five times more common among boys than girls, 1 in 54 boys and 1 in 252 girls identified; the largest demographic increases were among Hispanic and black children.
Dr. Marshalyn Yeargin-Allsopp, senior author of the CDC report, said that diagnosing ASDs can be difficult since there is no medical test, such as a blood test, to diagnose the disorders. Doctors usually have to analyze the child’s behavior and developmental progress to make a diagnosis, and using that diagnostic, ASDs can sometimes be detected as early as 18 months or younger. By age 2, a diagnosis by an experienced professional can be considered reliable, although many children do not receive a final diagnosis until much older – a delay that can mean that children with an ASD might not get the help they need when they need it.
Many children do not receive a final diagnosis until much older – a delay that can mean that children with an ASD might not get the help they need when they need it.
To help parents understand more about ASDs, Dr. Yeargin-Allsopp explained that diagnosing the disorder takes two steps. First, a developmental screening: A short test to tell if the child is learning basic skills when they should, or if they might have delays. During developmental screening the doctor might ask the parent some questions or talk and play with the child during an exam to see how he or she learns, speaks, behaves and moves. A delay in any of these areas could be a sign of a problem. Second, a comprehensive evaluation: A thorough review may include looking at the child’s behavior and development and interviewing the parents. It may also include a hearing and vision screening, genetic testing, neurological testing, and other medical testing.
Dr. Georgina Peacock, a medical officer and developmental-behavioral pediatrician with the Prevention Research Branch of the CDC’s National Center on Birth Defects and Developmental Disabilities works with health care professionals and early educators in ASD assessment and outreach.
Dr. Peacock recommends that all children be screened for developmental delays during regular well-child doctor visits, with standardized autism screening instrument at ages 9 months, 18 and 24 or 30 months. “More screening might be needed if a child is at high risk for developmental problems due to preterm birth, low birth weight or other reasons,” she noted. “Additional screening might be needed if a child is at high risk for ASDs (having a sister, brother or other family member with an ASD) or if behaviours sometimes associated with ASDs are present.”
There are red flags to look for at every developmental stage: Loss of skills at any age, ASD-associated behaviours such as headbanging, and even frequent headaches can be cause for concern (for a fuller list of signs of an ASD, check out the CDC’s checklist). And forewarned is forearmed – parents or carers can also monitor a child’s development and recognize the early warning signs of a developmental delay.
According to the CDC, there’s no single best treatment for all children with ASDs. However, well-planned, structured teaching of specific skills is crucial – and the earlier the intervention and treatment, the better.
For more information, please check with organizations that offer local support groups and information for families, including Autism Speaks and Parent to Parent. Special thanks to Conne Ward-Cameron at the CDC.
