Measuring Disability Through Self-Report

Increasingly, disability is an organizing principle for public health research and policy. The first objective in the Disability category for Healthy People 2020 is to “ Include in the core of Healthy People 2020 population data systems a standardized set of questions that identify ‘people with disabilities.' ” One reason that choosing a single set of questions is challenging is that there is no easy way to compare the different sets of questions proposed directly. We conducted a study to compare disability questions used on the Behavioral Risk Factor Surveillance Survey (BRFSS), the National Health Interview Survey (NHIS), and the American Community Survey (ACS). We also included the short set of questions proposed by the Washington City Group (Washington Group on Disability Statistics, 2010). More than 2,400 people responded to the Random Digit Dial survey that included all these disability questions along with other measures. We also conducted a followup survey with more than 500 respondents to evaluate the questions' test-retest reliability. Results revealed that the BRFSS questions identify different people than the functional limitation questions from other instruments. Small differences substantially affected both the oberved prevalences of different limitations and the reliability and validity of respondents' self-reports. These and other results are presented with considerations for researchers with different goals and specific recommendations for question structure and wording.