Selection of a validated scale for measuring medication adherence.

OBJECTIVE: To evaluate literature describing medication adherence surveys/scales to gauge patient behaviors at the point of care. DATA SOURCES: Literature was identified via PubMed and Ovid (1950 to June 2009) using the search terms medication adherence, medication compliance, and medication persistence and combined with the terms questionnaire, survey, scale, or self-report. STUDY SELECTION: All articles in English with adherence scales validated in two or more diseases and containing 30 or fewer questions were selected. DATA SYNTHESIS: Five adherence scales were identified and reviewed by evaluating positive characteristics (short length, internal consistency, reliability, barriers to adherence, literacy appropriate, and self-efficacy), sensitivity, specificity, and diseases in which they have been validated. The Medication Adherence Questionnaire (MAQ) is the shortest scale and easiest to score. MAQ identifies barriers to nonadherence but not self-efficacy. The Self-efficacy for Appropriate Medication Use Scale (SEAMS) is a 13-question scale, and the Brief Medication Questionnaire (BMQ) has three main question headings and multiple subquestions. Both assess barriers and self-efficacy; however, scoring is difficult. The Hill-Bone Compliance Scale and Medication Adherence Rating Scale (MARS) address barriers and self-efficacy but are limited in their generalizability. The Hill-Bone Compliance Scale focuses on hypertensive patients, while MARS is specific to psychiatric populations.
CONCLUSION: No gold-standard medication adherence scale exists. MAQ is most adaptable at the point of care and across populations. MAQ is the quickest to administer and score and has been validated in the broadest range of diseases. SEAMS, BMQ, and the Hill-Bone Compliance Scale allow self-efficacy to be assessed and therefore may be useful in medication management clinics. MARS is specific to psychiatric populations.