Assessing the Need for a National Disability Survey: Final Report. B. Improve Disability Measures in National Surveys


As outlined in Chapter II, national surveys include a variety of disability measures. Researchers have produced several theoretical frameworks to model disability, but translating these models into survey questions can be challenging. Although disability is a difficult concept to define and measure, efforts to develop a succinct but comprehensive set of questions to identify people with disabilities have great potential value. Such efforts led to a six-question series developed by an interagency work group, which is becoming the new standard for identifying disability in national surveys (Adler et al. 1999). These questions are now included in the CPS, ACS, AHS, and NHIS. In June 2011, HHS announced that, in response to new requirements in the Affordable Care Act, they have developed draft standards for the collection of survey data that, among other things, will require all federal surveys to include the six-question series on disability. The six-question series solicits information about hearing, vision, cognitive, ambulatory, self-care, and independent living disabilities.

Despite the considerable efforts to develop these questions, they appear to not capture a significant number of people that are identified by program administrators as having disabilities, and might miss others as well. In a recent paper, Burkhauser et al. (2010) find that in the noninstitutionalized population ages 25-61, the six-question sequence identifies only 65 percent of those who identify themselves as SSDI or SSI beneficiaries. They argue for the addition of a work-limitation question, similar to that used historically in the CPS, which by itself identifies approximately 84 percent of those reporting SSDI or SSI receipt in the 2009 CPS as having disabilities. Combining the six questions with the work-limitation question increases the percentage of beneficiaries identified as having disabilities to 92 percent.

It is important to note that this research uses self-reports of SSDI or SSI receipt, which might themselves be inaccurate. Follow-up research by Burkhauser and his co-authors will use CPS data matched to SSA data to validate self-reports of SSDI or SSI receipt and assess the extent to which the six-question series captures this population. They will also compare the SSA primary impairments of those captured by the various disability questions to the impairments of those not captured. This analysis will be able to assess the validity of a concern expressed by FAEP members: that the six questions do not adequately identify people with significant behavioral, emotional, and intellectual disabilities.

Though not without its limitations, the adoption of a common set of questions in surveys is nonetheless a positive contribution to the national disability data system. The addition of the six common questions across surveys was viewed by FAEP and TAG members as an important first step and suggests similar types of cross-survey questions could be developed in the future with effective collaboration efforts. While supportive of efforts to use a common set of disability questions in all federal surveys, TAG and FAEP members argued that complementary efforts were very important and needed to be pursued at the same time. These include:

  • Preserving the ability to produce trends by at least temporarily including old disability questions when new questions are added. For example, retaining the work-limitation question in the CPS would be beneficial for producing long-term trends.

  • Conducting research to better understand who is being captured by the six-question disability series, as well as who is not being captured. What types of impairments are and are not captured, and of what severity? What other characteristics distinguish those with disabilities who are captured from those who are not? Opportunities to study the six-question series will be available with data being collected for the 2010 and 2011 NHIS and the data planned for the re-designed SIPP. Since 2008 the NHIS has included the six-question series, along with numerous other measures of health and disability. Likewise, the re-designed SIPP will include the six-question series, a set of re-designed disability questions, and a module that will include questions contained in the former SIPP disability topical module that is being supported by SSA specifically to offer the opportunity to study the new SIPP disability questions and their implications.

  • Strategically adding disability questions to selected surveys, such as a work-limitation question or questions designed to identify specific conditions (for example, psychiatric or intellectual). The intent is to add detail that will be useful for the survey itself, but also provide information that illuminates the findings from other surveys that do not include the additional questions.

The FAEP and TAG members recognized that it will never be possible to develop a small set of questions that will perfectly distinguish between the disability and nondisability populations, nor even to reach agreement on who should be included in disability and nondisability populations. Instead, they think that the expanded use and better understanding of a consistent measure of disability would help answer a number of questions raised by federal and state agencies, despite the inherent flaws in any such measure. Notably, one agency commented, “To date, lack of standardization of the disability definition has made comparison across surveys difficult; there are even differences in the estimates of the number of people with disabilities.” The failure of the current system to consistently estimate statistics as basic as prevalence by any disability definition is a major shortcoming of existing data. At the same time, it is critically important to have a sophisticated understanding of any measure’s limitations, and to address those limitations through improvements in the measure when it is feasible to do so.

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