Reliability and known-group validity of the Arabic version of the 8-item Morisky Medication Adherence Scale among type 2 diabetes mellitus patients

ABSTRACT

No validation study has previously been made for the Arabic version of the 8-item Morisky Medication Adherence Scale [MMAS-8©] as a measure for medication adherence in diabetes. This study in 2013 tested the reliability and validity of the Arabic MMAS-8 for type 2 diabetes mellitus patients attending a referral centre in Tripoli, Libya. A convenience sample of 103 patients self-completed the questionnaire. Reliability was tested using Cronbach alpha, average inter-item correlation and Spearman-Brown coefficient. Known-group validity was tested by comparing MMAS-8 scores of patients grouped by glycaemic control. The Arabic version showed adequate internal consistency [alpha = 0.70] and moderate split-half reliability [r = 0.65]. Known-group validity was supported as a significant association was found between medication adherence and glycaemic control, with a moderate effect size [phic = 0.34]. The Arabic version displayed good psychometric properties and could support diabetes research and practice in Arab countries