Item response theory and its applications to patient-reported outcomes measurement

This article provides an overview of item response theory (IRT) models and how they can be appropriately applied to patient-reported outcomes (PROs) measurement. Specifically, the following topics are discussed: (a) basics of IRT, (b) types of IRT models, (c) how IRT models have been applied to date, and (d) new directions in applying IRT to PRO measurements.