Self-reported medication adherence measurement tools: Some options to avoid a legal minefield.

What is known and objective: Self-report questionnaires are used to measure medication adherence, often times both clinically and for research purposes. Despite the presence of several published tools, some may have prohibitive licensure and fee requirements, which researchers should be aware of prior to using them. This paper presents a summary of selected self-report measures, which have been developed and validated in various health conditions and can be used free of cost. Comment: Our review identified self-report tools that are valid to measure medication adherence in different chronic health conditions. Most of these tools measure both intentional and unintentional non-adherence and have shown good correlation with relevant clinical outcomes. What is new and conclusion: Given the potential copyright risks associated with using some of the self-report measures of adherence, an improved awareness and understanding of the available self-report questionnaires will better facilitate the decision by researchers to select appropriate tools relevant to their studies.