METHODS: Data from three population-based health surveys, the 2014 Behavioral Risk Factor Surveillance System (BRFSS), the 2013-14 National Health and Nutrition Examination Survey (NHANES), and the 2014 National Health Interview Survey (NHIS), are used to estimate the prevalence and population estimates of disability among adults 18 years of age or older. Comparisons of the measures of disability both within and across surveys are described.
RESULTS: Using similar questions to measure disability (which may include limitations in vision, hearing, cognition, mobility, self-care and independent living), prevalence estimates varied by survey: 17.1% (NHIS), 22.2% (NHANES), and 23.3% (BRFSS); these represent a range of 40.2 million to 54.7 million U.S. adults. When measuring disability using only two questions (i.e., general activity limitation and special equipment use) in BRFSS, it is estimated that 23.0% of adults have a disability. Using a definition of disability that measures limitation in several additional domains (including limitations in social and work functioning), approximately one-third of adults are identified as having a disability in both NHIS (33.9%) and NHANES (33.6%); these estimates equate to 78.5 million and 76.5 million adults, respectively.
CONCLUSIONS: The differences in estimates demonstrate the complexity of measuring disability in population-based surveys. Factors related to the survey, such as mode of data collection, sampling frame, the use of proxy respondents, and the questions themselves, can result in different estimates. Regardless of the definition, construct and data source used, adults with disabilities represent a large subpopulation in the U.S., and one that is known to experience health disparities. Therefore, understanding these differences and the factors related to them can help public health programs include adults with disabilities as a subpopulation in their analyses, program planning and reporting.