Validation of the Persian Version of the 8-Item Morisky Medication Adherence Scale (MMAS-8) in Iranian Hypertensive Patients
Objectives. To assess adherence to long-term medications among patients in family medicine clinics and to evaluate relationship between adherence, beliefs about medications, medication information adequacy, and other factors. Methods. Interviewer assisted survey was conducted to assess adherence using the 8-item Morisky Medication Adherence Scale (MMAS-8), beliefs about medications using beliefs about medicine questionnaire (BMQ), and the patients' perception of medication information adequacy. Results. Of the 408 participants, 56.9% reported low adherence. Pearson's bivariate correlation showed positive association between MMAS-8 score and BMQ-specific necessity (r = 0.526 P < 0.001) and the perceived information adequacy (r = 0.568 P < 0.001), and there was negative association between adherence score and BMQ specific concerns, general overuse, and harm (r = -0.647, -0.466, and -0.663, resp.) (P < 0.001). Multivariable analysis revealed that age, number of medications, number of medical conditions, specific necessity and concerns beliefs, general harm beliefs, and perceived adequacy of medication information were independent predictor of adherence. Furthermore, specific beliefs explain 27.7% of the variance in adherence, while medication information adequacy explains 32.3% of the variance in adherence. Conclusion. The prevalence of low adherence among patients on long-term medications is high and it is related to negative beliefs about medications and to inadequate information given to patients about their medications.