Increasing Prevalence of Developmental Disabilities Among Children in the US: A Sign of Progress?

Abstract

The most recent update on developmental disabilities from the National Health Interview Survey (NHIS) report “Prevalence and Trends of Developmental Disabilities among Children in the United States: 2009–2017” reveals a 9.5% increase in prevalence over 9 years.1 This increase is the latest increment in the rising prevalence of childhood disabilities documented by NHIS data since the 1960s.2 Since 1997, when the NHIS began using questions similar to those it uses today to monitor disabilities among children aged 3 to 17 years, the prevalence has increased by 38% to nearly 18% of children, or >1 in 6.1 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.Similar trends have been reported from other countries3,4 and are likely a consequence of improvements in child survival, especially improvements that extend to children at high risk of disability due to risk factors such as preterm birth, brain trauma, and congenital conditions such as Down syndrome. 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.5Other positive factors driving the trend of increasing prevalence of developmental disabilities could include improvements in knowledge and awareness of neurodevelopment on the part of health care providers, parents, and educators; broadening of diagnostic criteria to include a spectrum of behavioral and functional limitations; improvements in developmental screening and access to diagnostic and treatment services; and improvements in the social inclusion of children with disabilities. In the 1960s, using a narrower definition than it uses today, the NHIS found a prevalence of child disability of ∼2%.2 At that time, children with disabilities were often in institutional care and may not have been counted by the NHIS because of its restriction to the noninstitutionalized population. It was not until 1975 that children with disabilities were guaranteed the right to a free and appropriate public education.6 After deinstitutionalization and the emergence of inclusive education, significant advances have been made in awareness, acceptance, and social inclusion of children with developmental disabilities, although additional progress is needed. Inasmuch as the rising trend in childhood disability documented by the NHIS provides a measure of these advances, the trend may be a sign of progress.Zablotsky et al1 begin by defining developmental disabilities as lifelong impairments arising in childhood. They conclude the report by citing evidence that early identification of children at risk for disability and effective therapeutic interventions from an early age can improve long-term outcomes and, for some children, result in loss of their disability status. This suggests another hopeful interpretation of the rising prevalence of developmental disabilities. To the extent that the rise is due to enhanced pediatric screening, diagnostic services, and access to effective early interventions, we might expect reductions in disabilities over the life course among the expanding population receiving services for developmental disabilities during childhood. This would, of course, require sustained investments in early child education and pediatric services that are commensurate with the number of children at risk for developmental disabilities. Available data clearly support the conclusion that such investments are warranted.The detailed tables in the article by Zablotsky et al1 include many other notable findings. The rise in prevalence between 2009 and 2017 was driven by increases in autism spectrum disorder (ASD), intellectual disability, and attention-deficit/hyperactivity disorder (ADHD), whereas prevalence of cerebral palsy, hearing loss, and seizures declined over time. This is consistent with a previous analysis of NHIS data that revealed increases during recent decades are seen only for childhood disabilities classified as mental or behavioral7 and with surveillance data revealing a secular decline in the prevalence of cerebral palsy among US children.8Other important findings in the report point to potential disparities in access to care. Children classified as black non-Hispanic had the highest prevalence of developmental disabilities overall and of cerebral palsy, learning disability, intellectual disability, seizures, and speech impairments specifically. White non-Hispanic children had the highest prevalence of ASD and ADHD, whereas Hispanic children had the lowest prevalence of each type of disability except for blindness. Increasing levels of maternal education appeared to be protective against all types of developmental disabilities except for ASD and ADHD, which were most prevalent in children of college-educated mothers. Rural-urban differences were also found, with all types of disability except ASD and speech impairments being more prevalent in rural communities.The value of the NHIS data for monitoring long-term trends and disparities in the prevalence of disabilities among US children is difficult to overstate. With the publication of these findings, the need for expanded services and training to meet the needs of children with developmental disabilities cannot be ignored.