Estimates indicate that 1 out of 150 children will be diagnosed with an autism spectrum disorder (ASD), but most will not be diagnosed until they are almost ready to start kindergarten.
Amy Wetherby, the L.L. Schendel Professor of Communication Disorders at Florida State University, has received a four-year grant expected to total nearly $1.4 million from the Centers for Disease Control and Prevention to determine the prevalence of ASD in children under age 4. The new study will expand Wetherby’s FIRST WORDS Project, an early identification and intervention program, by screening 16,000 children in North Florida.
“There is not yet a biological marker for ASD, so the diagnosis of ASD is based on a set of behavioral features,” Wetherby said. “Our efforts to screen a general population sample through the FIRST WORDS Project have provided the research to help us know the early signs. This new CDC study will provide more research to further refine those early signs.”
The CDC selected FSU and a site in California to be the first to determine the prevalence of autism disorders in children under 4. The median age of diagnosis in the United States is about 4 1/2, according to the CDC-funded Autism and Developmental Disabilities Monitoring Network. Earlier this year, the network released the results of a study that indicated 1 out of 150 children at age 8 have an ASD.
Along with communication disorders faculty member Lindee Morgan, Wetherby will focus on the prevalence of an ASD at two ages in early childhood, 18 and 30 months. Identifying ASD early will allow experts to begin early intervention efforts to boost social, language and cognitive skills and hopefully improve outcomes, she said.
“Because we will be the first to determine prevalence at this young age, I’m not sure what we will find,” Wetherby said. “Maybe it will be the same as in 8-year-olds or maybe it will be higher, which may mean that some children show the symptoms very early and then some clear up. Then again, maybe it will be lower, which means that fewer children show the symptoms early and it does not fully unfold until later. We won’t know until we do the study. It also will be important to see if we find any differences between the two ages of 18 and 30 months.”
Children will be recruited from a representative sample of 16,000 children born between April 2006 and March 2010 in 12 Florida Panhandle counties. Doctors and childcare providers will be asked to give parents a checklist of appropriate use of words, sounds, gestures and behaviors for children between 9 and 18 months old. Children who fail the screening and randomly selected children who pass will be invited to complete an autism-specific screening when they are between 10 and 18 months old.
Symptoms of ASD in babies and toddlers include a lack of typical behaviors for this age group, such as looking at faces, smiling and sharing emotion, communicating with gestures and playing with objects, according to Wetherby. They also may have unusual behaviors that typical children do not display, such as repetitive movements with the body or objects.
As part of the new CDC project, Wetherby will estimate the validity of the parent checklist and compare other autism screening tools. She also will describe demographic and developmental characteristics of the study sample, which includes about half of the children born in Bay, Calhoun, Franklin, Gadsden, Gulf, Holmes, Jackson, Jefferson, Leon, Liberty, Wakulla and Washington counties during the four-year period of the study.
“I also hope to identify barriers that may impede the screening and referral process and develop strategies to improve it,” Wetherby said. “We will conduct focus groups with parents and professionals to seek input on how to improve the screening process and offer better ways to share information about initial diagnosis and access to services.”