Background: The term "developmental disability" (DD) is inconsistently defined and applied depending on purpose and across sources, including in legislation.
Objective: This project aimed to identify existing definitions of disability and DD and to determine the extent to which each definition could be operationalized to produce prevalence estimates using data from U.S. national surveys.
Methods: Using data among children <18 years from the 2016-2018 National Health Interview Survey (NHIS) and National Survey of Children's Health (NSCH), we estimated the prevalence of two definitions of disability (Washington Group Short Set on Functioning, American Community Survey) and seven definitions of DD [Health and Human Services (ever/current), Developmental Disabilities Assistance and Bill of Rights Act of 2000 (1+, 2+, or 3+ components), and Diagnostic and Statistical Manual of Mental Disorders, 5th ed (ever/current)]. Complex sample design variables and weights were used to calculate nationally representative prevalence.
Results: Disability (NHIS: 5.2-6.3%; NSCH: 9.2-11.9%) and DD prevalence (NHIS: 0.6-18.0% and NSCH: 0.2-22.2%) varied depending on the definition and data source. For the same definition, NSCH prevalence estimates tended to be higher than NHIS estimates.
Conclusions: The substantial variability in estimated prevalence of disability and DD among children in the United States may be in part due to the surveys not representing all components of each definition. Different or additional questions in national surveys may better capture existing definitions of disability and DD. Considering the data collection goals may help determine the optimal definition to provide useful information for public health action.
Keywords: Definition; Developmental disability; Disability; Measurement; Measurement purpose.
Published by Elsevier Inc.