The eight-item Morisky Medication Adherence Scale MMAS: Translation and validation of the Malaysian version

Aims: To translate and examine the psychometric properties of the Malaysian version of the Morisky Medication Adherence Scale (MMAS) among patients with type 2 diabetes. Methods: A standard "forward-backward" procedure was used to translate MMAS into Malay language. It was later validated on a convenience sample of 223 type 2 diabetes outpatients between May and September 2009. Reliability was tested for internal consistency. Validity was confirmed using convergent and known group validity. Results: Employing the recommended scoring method, the mean +/- SD of MMAS scores was 6.13 +/- 1.72. Moderate internal consistency was found (Cronbach's alpha = 0.675), the test-retest reliability value was 0.816 (p < 0.001). A positive correlation between the eight- and four-item MMAS was found (r = 0.792; p < 0.01). A significant relationship between MMAS categories and HbA1c categories (chi(2) = 20.261; p >= 0.001) was found. The MMAS sensitivity and specificity, with positive and negative predictive values were 77.61%, 45.37%, 46.84% and 76.56%, respectively. Conclusions: The findings of this validation study indicate that the Malaysian version of the MMAS is a reliable and valid measure of medication adherence which can now be used. (C) 2010 Elsevier Ireland Ltd. All rights reserved.