Concordance of Pharmacist Assessment of Medication Nonadherence With a Self-Report Medication Adherence Scale

Abstract

Objective: To evaluate the concordance of the Modified Morisky Scale (MMS) with a pharmacist assessment of medication adherence during a medication review.

Methods: This retrospective study examined the electronic medical records (EMRs) of patients ≥18 years who received a medication review by a pharmacist from October 2008 to September 2009 at a homeless behavioral health clinic. In addition to the 6-item MMS, adherence was assessed using the first 4 items of the MMS, which comprise the original Morisky Scale. A final pharmacist assessment of adherence based upon the medication review was documented in the EMR. The McNemar test was used to assess the agreement between the MMS (6 and 4 items) and the pharmacist assessment of medication adherence.

Results: A total of 288 patients were eligible for the study, which included 449 medication reviews. Nonadherence was identified in 61.7% and 49.7% of medication reviews using the 6 and 4 items of the MMS. The pharmacist assessment determined nonadherence in 23.8% of medication reviews. There were significant differences between the pharmacist adherence assessment and the 6 (P < .0001) and 4 (P < .0001) items of the MMS.

Conclusion: A combination of methods including self-report and pharmacist assessment may provide the greatest insight into adherence.

Keywords: medication adherence; medication therapy review; pharmacist; self-report scale.