Objective: To evaluate the association and concordance of the new 8-item self-report Morisky Medication Adherence Scale (MMAS) with pharmacy fill data in a sample of community-dwelling seniors with hypertension.
Study design: Cross-sectional study.
Methods: Pharmacy records for antihypertensive medications were abstracted for 87 managed care adult patients with hypertension 65 years and older who completed a survey that included the MMAS. Continuous single-interval medication availability (CSA), medication possession ratio (MPR), and continuous multiple-interval medication gaps (CMG) were calculated using pharmacy data. The MMAS adherence was categorized as high, medium, and low (MMAS scores of 8, 6 to <8, and <6, respectively); pharmacy fill nonpersistence was defined as less than 0.8 for CSA and MPR and as greater than 0.2 for CMG.
Results: Overall, 58%, 33%, and 9% of participants had high, medium, and low medication adherence, respectively, by the MMAS. After adjustment for demographics and in comparison to high adherers on the MMAS, patients with low MMAS adherence were 6.89 (95% confidence interval [CI], 2.48-19.10) times more likely to have nonpersistent pharmacy fill adherence by CSA and were 5.22 (95% CI, 1.88-14.50) times more likely to have nonpersistent pharmacy fill adherence by MPR. Concordance between the MMAS and CSA, MPR, and CMG was 75% or higher.
Conclusions: The MMAS is significantly associated with antihypertensive drug pharmacy refill adherence. Although further validation of the MMAS is needed, it may be useful in identifying low medication adherers in clinical settings.