There are many factors and tradeoffs to consider in weighing the value of developing a periodic national disability survey versus utilizing other means that leverage existing data collection effort to address disability data limitations. Here, we discuss some of the advantages and disadvantages of conducting a national disability survey.
A primary advantage of a national disability survey is that, as a new data collection effort, it could be designed to specifically address particular existing data limitations. As existing surveys have specific focuses, adding questions of interest outside of the topic areas of these surveys seems unlikely. Another important advantage over other options stems from the fact that statistics would be based on a single set of disability identifiers and obtained from data that were collected using a single methodology. Even if consistent disability indicator questions were used across different national surveys, differences in how the surveys are administered inevitably would lead to differences in the estimates and characteristics of the population of people with disabilities identified.
In a new national disability survey, the identification of people with disabilities who are often overlooked (for example, people with specific disabilities, with difficulties responding to a particular survey format, or living in institutional settings) could be prioritized. For existing surveys that do not cover people in such populations, changes to the sampling framework and implementation will be costly and may reach beyond the realm of moderate modifications. Although the cost will be lower relative to a new, stand-alone survey, it may be difficult to convince the agencies that oversee these surveys to make such changes.
A national survey would also have the potential to provide a complete life cycle perspective on disability, which seem to be missing from existing data. Several current surveys, such as the HRS, provide ample disability-related information, but only for a specific age group (the elderly). Other surveys focus on children and education, such as the NLSY. Few surveys provide a breadth of detailed disability-related information on all age groups.
Support for a national disability survey was expressed by the majority of FAEP and TAG participants. One participant noted that the United States is one of the only industrialized nations without a national disability survey, to which another responded that it was time for an ambitious project in the United States. Administrative data, survey data, and efforts to advance the state of disability research were described as fragmented. A combined national project has the power to unify the fragmented system and to provide a wide array of information on people with disabilities without having to link across or otherwise use data from numerous surveys.
The creation of a national disability survey is associated with several disadvantages and potential challenges. The primary concerns related to such an effort are the potential expense and difficulty in design and implementation. The NHIS-D was large, costly, and complex. It involved funding from and coordination across numerous federal agencies. Decisions regarding who is responsible for funding and development, the topics to include, sample sizes, how the sampling frame is to be derived, and how the survey will be administered would need to be negotiated among the various sponsors. TAG participants expressed concern about funding and coordination as well. The group noted that securing the funding for such a large project would be difficult, and disability advocates may not be in favor of federal spending on survey research, preferring instead that the resources to be devoted to programs and services.
Problems arise for both a stand-alone survey and a supplement. If not connected with an existing national survey, comparative information on people without disabilities would either be unavailable or the sample would need to include people without disabilities, thereby substantially increasing the sample size and cost of the survey. A longitudinal survey excluding people without disabilities would be limited in its ability to gain a lifetime perspective on people with disabilities, as disability onset would not be captured. This limitation may be somewhat addressed by the use of retrospective questions related to disability onset, but it will be difficult to capture detailed information around this transition due to issues related to memory recall (particularly for individuals who have been living with a disability for an extended period of time and for those with substantially limited memories).
If connected with an existing national survey, addition of the disability supplement would need to be negotiated with the sponsors of the parent survey, and disability screening questions would likely need to be added. Parent survey sponsors might be averse to adding extensive screening questions to an existing survey if it poses a risk that answers to other questions in the survey will systematically differ from those in earlier or later rounds because of changes in the context of those questions.
There is too much potential topical content for a national disability survey to incorporate it in one survey. As mentioned by one of the FAEP participants, there is interest in more than just the health of people with disabilities. Accordingly, a survey intending to capture the many effects of disability would need to include a large number of topics. However, this would lead to a survey that would likely be prohibitively long, which may lead to a low completion rate and be expensive. This could be addressed in longitudinal survey through topical modules, or in a large cross-sectional survey via random use of some question modules across respondents.
Of all of the approaches described for addressing disability data limitations, a national disability survey is perhaps the most ambitious. It is difficult to imagine, however, that a periodic national disability survey alone could meet the needs and address all the unanswered questions raised by federal and state agency staff, given the wide range of issues and subpopulations they encompass. Yet such a survey might provide important data to address a subset of issues deemed to be of the highest priority.