Children with autism spectrum disorder (ASD) are being identified at earlier ages, which can improve outcomes. However, gaps in evaluation remain, according to a new study.
The research underscored why pediatricians should follow AAP recommendations on screening children for developmental delays at 9, 18 and 24 or 30 months and specifically for ASD at 18 and 24 months.
“Primary care pediatricians through the medical home are really in a unique position to promote early identification of children with a possible diagnosis of autism spectrum disorder through the strategies of developmental surveillance and regular use of autism screening tools at targeted times,” Susan E. Levy, M.D., M.P.H., FAAP, chair of the AAP Autism Subcommittee, said Thursday during a telebriefing coordinated by the Centers for Disease Control and Prevention (CDC).
When looking at prevalence of ASD, researchers typically use data on 8-year-olds from the CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network. However, they recently piloted a project known as Early ADDM to study ASD in 4-year-olds from five of the 11 communities in the ADDM.
“While the larger ADDM network provides a more complete estimate of the number of children with autism by tracking 8-year-olds, data from Early ADDM can help us understand the characteristics of children who are identified early and can inform efforts to get children identified and connected to services as soon as possible,” said Nicole Dowling, Ph.D., a CDC epidemiologist.
The research is detailed in the report “Prevalence and Characteristics of Autism Spectrum Disorder Among 4-Year-Old Children in the Autism and Developmental Disabilities Monitoring Network” (Christensen DL, et al. J Dev Behav Pediatr. Dec. 9, 2015, bit.ly/1Q3Ge2G).
Looking at school and health records from 2010, the team found the prevalence of ASD in 4-year-olds to be 13.4 per 1,000, which is about 30% lower than among 8-year-olds. They said the difference may be due to diagnosis typically occurring after age 4 or 5.
The most accurate prevalence rate still is one in 68 children, which is based on data from 8-year-olds. That figure is expected to be updated in the spring.
The team also found higher rates of intellectual disability among 4-year-olds with ASD than 8-year-olds with ASD.
“It may be that children who have more severe ASD-related behaviors or who have other conditions like intellectual disability are more likely to be evaluated at a younger age,” said Deborah “Daisy” Christensen, Ph.D., a CDC epidemiologist and lead author of the report.
Experts said more work is needed to increase awareness about ASD among black families as those children did not receive a comprehensive evaluation by age 3 at as high a rate as white children.
Still, they were encouraged by the overall finding that among children diagnosed by age 4, the median age for a comprehensive evaluation was five months earlier for the children born in 2006 than for those born in 2002.
“It’s five months that a mother or father doesn’t have to spend questioning their child’s development and behavior or questioning whether they should be doing more to help him,” said Alison Singer, M.P.H., co-founder and president of the Autism Science Foundation. “It’s five fewer months of painful uncertainty. … It’s also five months of intervention during the period of time when intervention can do the greatest good because the brain is most malleable.”
