The significant increase in developmental disability prevalence in U.S. children from 2009 to 2017 may have been driven by factors such as better identification and availability of services, according to analysis of National Health Interview Survey (NHIS) data.

Disabilities with significant increases in children aged 3-17 years

The prevalence of any developmental disability rose from 16% in 2009 to 18% in 2017 in children aged 3-17 years, for an increase of 9.5%, Benjamin Zablotsky, PhD, of the National Center for Health Statistics, Hyattsville, Md., and associates reported in Pediatrics.

Changes among the various conditions were not uniform, however, and most of the increase came from ADHD, autism spectrum disorder (ASD), and intellectual disability, which were up by 12.6%, 122.3%, and 25.8%, respectively, they said, based on data for 88,530 children from the NHIS.

Because other studies have shown that the “prevalence of ADHD symptoms and impairment has remained steady over time,” the increase according to NHIS data “could be driven by better identification of children who meet criteria for ADHD, as current estimates of diagnosed prevalence are in line with community-based studies,” Dr. Zablotsky and associates wrote.

Improved identification, “related to increasing parental awareness and changing provider practices” also may account for much of the rise in ASD prevalence, they said.

It also may be related to changes in the survey itself, as “an increase of about 80% was seen in the 2014 NHIS following changes to the wording and ordering of the question capturing ASD.”

The investigators offered a similar explanation for the increase in intellectual disability prevalence, which increased by 72% from 2011 to 2013 when the phrasing of the NHIS question was changed from “mental retardation” to “intellectual disability, also known as mental retardation.”

The other specific conditions – blindness, cerebral palsy, hearing loss, learning disability, seizures, and stuttering/stammering – all saw nonsignificant changes during the study period, with one exception. “Other developmental delay” dropped by a significant 13%. “It is possible that parents have become less likely to select this category because their children have increasingly been diagnosed with another specified condition on the survey,” Dr. Zablotsky and associates said.

“These findings have major implications for pediatric training and workforce needs and more broadly for public health policies and resources to meet the complex medical and educational needs of the rising number of children with disabilities and their families,” Maureen S. Durkin, PhD, DrPH, said in an accompanying editorial.

The trends reported by Dr. Zablotsky and associates, which have been seen in other countries, are the result of improved survival among children, so, “in this sense, a rise in the prevalence of developmental disabilities may be seen as a global indicator of progress in children’s health and pediatric care,” said Dr. Durkin, a epidemiologist in Madison, Wis.

Dr. Zablotsky and coauthors said that there was no external funding for the study and that they had no relevant financial relationships to disclose. Dr. Durkin said that she had no potential conflicts of interest.

SOURCES: Zablotsky B et al. Pediatrics. 2019 Sep 26. 144(4):e20190811. doi: 10.1542/peds.2019-0811; Durkin MS. Pediatrics. 2019 Sep 26. 144[4]:e20192005. doi: 10.1542/peds.2019-2005.