Conceptualizing disability in US national surveys: application of the World Health Organization's (WHO) International Classification of Functioning, Disability, and Health (ICF) framework.

Purpose: Disability data inform resource allocation and utilization, characterize functioning and changes over time, and provide a mechanism to monitor progress toward promoting and protecting the rights of individuals with disability. Data collection efforts, however, define and measure disability in varied ways. Our objective was to see how the content of disability measures differed in five US national surveys and over time.

Methods: Using the WHO ICF as a conceptual framework for measuring disability, we assessed the National Health Interview Survey (NHIS), Current Population Survey (CPS), Survey of Income and Program Participation (SIPP), National Survey of SSI Children and Families (NSCF), and American Community Survey (ACS) for their content coverage of disability relative to each of the four ICF components (i.e., body functions, body structures, activities and participation, and environment). We used second-level ICF three-digit codes to classify question content into categories within each ICF component and computed the proportion of categories within each ICF component that was represented in the questions selected from these five surveys.

Results: The disability measures varied across surveys and years. The NHIS captured a greater proportion of the ICF body functions and body structures components than did other surveys. The SIPP captured the most content of the ICF activities and participation component, and the NSCF contained the most content of the ICF environmental factors component.

Conclusions: This research successfully illustrated demonstrated the utility of the ICF in examining the content of disability measures in five national surveys and over time.