Medication adherence: A practical measurement selection guide using case studies.

OBJECTIVES: Medication adherence is a complex problem and can be evaluated using a variety of methods. There is no single or perfect strategy to assess adherence. The "best" measure depends on contextual factors. Our objective is to provide a practical, illustrative guide for selecting the most appropriate measure of medication adherence in common contexts.

METHODS: We present three case studies - from the perspectives of an academic researcher, health care payer, and clinical care provider - to describe common problems and processes for measuring medication adherence, as well as proposing possible solutions.

RESULTS: The most appropriate measure will depend on the context (tightly controlled clinical trial setting vs. clinical setting), intended purpose (research vs. clinical), available resources (data, personnel, materials, and funding), time (quick screening vs. comprehensive review), and phase of interest (initiation, implementation, or discontinuation). Framing the problem of medication non-adherence and methods for measuring adherence are discussed using three representative case studies.

CONCLUSIONS: A simple tool is provided that may help stakeholders interested in medication adherence make decisions regarding the appropriate selection of measures.

PRACTICE IMPLICATIONS: A medication adherence measure should be selected through the lens of each situation's unique objectives, resources, and needs.