Development of a Short-Form of the Medication Management Test: Evaluation of Dimensionality, Reliability, Information and Measurement Equivalence Using Latent Variable Models.

Background and Purpose: The Medication Management Test (MMT) measures higher cognitive functioning. The aim of the analyses presented was to reduce assessment burden by developing a short-form version, and describe its psychometric properties. Methods: Factor analyses, item response theory (IRT), and differential item functioning (DIF) were performed to examine the dimensionality, reliability information, and measurement equivalence. Results: The ratio of the first two extracted eigenvalues from the exploratory principal component analysis was 7.62, indicating essential unidimensionality. Although one item "needs prompting for pill regime" evidenced DIF above the threshold for education and race/ethnicity, the magnitude was relatively small and the impact minimal. IRT-based reliability estimates were high (>0.80) across all subgroups. Conclusions: Because medication management is an important task associated with independent living, it is critical to assess whether medications can be self-administered safely.