An Assessment of the Representativeness of the SSI DA&A Study Panels
In this study, we used data derived from SSA administrative records to compare the composition of study panels, study samples, and the national population of former recipients of Supplemental Security Income (SSI) for drug addiction and alcoholism (DA&A). We found that the panels represented the selected samples in the nine-study sites in terms of demographics, SSI program status, and medical eligibility. However, the selected samples varied in how well they represented their target populations. Additionally, compared with the national DA&A population, SSI Study respondents were more likely to be black, to abuse both drugs and alcohol, to be more concentrated in the 30-49 age range, and to have been medically eligible for SSI in January and June 1997. Thus while the SSI Study data can be used to draw inferences about former DA&A SSI-only recipients in the study catchment areas, results should not be assumed to apply to the national population of such recipients.