Calculating medication compliance, adherence and persistence in administrative pharmacy claims databases

Compliance, adherence, and persistence are outcomes easily measured in pharmacy claims databases. However, these measures are used with differing taxonomies and the calculations are heterogeneous. The results can then lead to spurious interpretations. Therefore, the research community would benefit from a common set of definitions and methods to calculate compliance and persistence. This paper briefly explains the definitions of compliance and persistence based on the guidance from the Medication Compliance and Persistence Special Interest Group of ISPOR, the International Society for Pharmacoeconomics and Outcomes Research, and provides analytic methods that are congruent with the preferred terminology.