Methodological note: Allocation of disability items in the American Community Survey

BackgroundDetermining the prevalence and correlates of disability requires the use of sample surveys in data analysis. In an effort to generate complete datasets, allocation procedures (i.e., the assignment of values to missing or illogical responses) are frequently used for missing or inconsistent responses.ObjectivesThe goal of this investigation was to explore how six disability-related questions vary in their degree of allocation and how research results may be sensitive to this procedure. This is important because many researchers using large disability information banks are not survey methodologists and may be unaware of how the Census Bureau's editing procedures can influence research findings.MethodsWe use 2010 1-year Public Use Microdata Sample files from the American Community Survey (ACS). We investigated the allocation rates of the following disability items: self-care; hearing; vision; independent living; ambulatory; and cognitive ability. We also asked how allocation rates varied by demographic characteristics and whether the allocated values could influence multivariate results.ResultsDisability item allocation in ACS data have detectable patterns, where the rate of disability allocation is higher for mail surveys, males, older people, groups who speak English not well or not at all, US citizens, Latinos(as), and for people living in or near poverty. Multivariate models may be sensitive to how these allocated values are treated.ConclusionsThe rate of allocations varies as a function of demographic variables because of methodological procedures and survey participation behaviors. Because allocation rates may affect research and policy about the disabled population, more research is required.