RESUMEN
Background: Hypertension is a global public health crisis. Poorly controlled high blood pressure is one of the most important factors contributed to this crisis. Lack of medication adherence is often considered as the main reason for insufficient control of high blood pressure. Difficulty in measuring medication adherence is another problem in this field. To reduce this difficulty several medication adherence scales were developed. This study was performed to test reliability and validity of Morisky Medication Adherence Scale-8. Materials and Methods: A cross-sectional study was conducted to validate the Persian version of MMAS-8. The Persian version of MMAS-8 was generated by using a modified forward/backward translation procedure. Two hundred and fifty hypertensive patients were participated in the study. Construct and known-groups validity, Cronbach’s alpha and test-retest reliability were used to assess psychometric properties of Persian scale. Results: Data analysis showed that the scale did not have an acceptable internal consistency (Cronbach’s Alpha= 0.40) but had excellent stability (p= 0.89). The confirmatory factor analysis poorly fitted with one-dimensional model. Participants with controlled blood pressure had significantly higher MMAS-8 scores than uncontrolled blood pressure group. Conclusion: Totally some of the psychometric properties of the Persian version of the MMAS-8 did not meet the requirements of the standard level so it is not recommended to use in general. More studies are needed to establish a more appropriate scale in order to be used in the mentioned population.
RESUMEN
Introduction: Hypertension is a global public health concern. Among the factors that contribute to this crisis, the poor control of hypertensive patients is a major concern. Patients’ lack of adherence to the medication regimen is often considered to be the main reason for this failure. Several medication-adherence scales were designed to measure the extent to which patients adhere to their medication and treatment regimens. Since these scales must be very reliable and have strong validity if they are to be used in clinics and research, this study was performed to test the reliability and validity of the Hill-Bone’s scale of “Compliance to High Blood Pressure Therapy.” Methods: After using a modified forward/backward translation procedure to create a Persian version of the Hill-Bone’s scale, we conducted a cross-sectional study in which two hundred and eighty hypertensive patients participated to validate the Persian version. Exploratory and confirmatory factor analysis, criterion validity, Cronbach’s alpha, and test-retest reliability were used to determine the validity and reliability of the Persian scales’ psychometric properties. Results: The analysis of the data showed that the scale had excellent stability (Intraclass Correlation Coefficient = 0.97) and low acceptability of internal consistency (Cronbach’s Alpha = 0.44). The exploratory factor analysis did not clarify meaningful patterns among the subscales. The confirmatory factor analysis failed to fit the observed items with the latent subscales. The scale scores were not correlated with blood pressure (P > 0.05). Conclusion: Although some of the psychometric properties of the Persian version of the Hill- Bone’s scale and its modified version were acceptable, they were not sufficient to recommend the Persian version for general use. More studies are needed to revise and develop a more comprehensive scale that is appropriate for use in the context of the mentioned population.