Determinants of medication adherence among adults with type 2 diabetes mellitus in three Malaysian public health clinics: a cross-sectional study

Medication adherence (MA) in adults with type 2 diabetes mellitus (T2D) is associated with improved disease control (glycated hemoglobin, blood pressure, and lipid profile), lower rates of death and diabetes-related complications, increased quality of life, and decreased health care resource utilization. However, there is a paucity of data on the effect of diabetes-related distress, depression, and health-related quality of life on MA. This study examined factors associated with MA in adults with T2D at the primary care level. This was a cross-sectional study conducted in three Malaysian public health clinics, where adults with T2D were recruited consecutively in 2013. We used the 8-item Morisky Medication Adherence Scale (MMAS-8) to assess MA as the main dependent variable. In addition to sociodemographic data, we included diabetes-related distress, depressive symptoms, and health-related quality of life as independent variables. Independent association between the MMAS-8 score and its determinants was done using generalized linear models with a gamma distribution and log link function. The participant response rate was 93.1% (700/752). The majority were female (52.8%), Malay (52.9%), and married (79.1%). About 43% of patients were classified as showing low MA (MMAS-8 score <6). Higher income (adjusted odds ratio 0.90) and depressive symptoms (adjusted odds ratio 0.99) were significant independent determinants of medication non-adherence in young adults with T2D. Low MA in adults with T2D is a prevalent problem. Thus, primary health care providers in public health clinics should focus on MA counselling for adult T2D patients who are younger, have a higher income, and symptoms of depression.