Association between the 8-item Morisky medication adherence scale (MMAS-8) score and glycaemic control among Chinese diabetes patients

Adherence with oral hypoglycaemic agent is crucial to achieve optimal glycaemic control. The 8-item Morisky Medication Adherence Scale (MMAS-8) has been frequently used, yet the association between MMAS-8 score and glycaemic control among Chinese diabetes patients is largely unknown. Two general out-patient clinics were randomly selected in a district with socio-demographic characteristics representative of the entire Hong Kong population. A consecutive sample of adult type-2 diabetes patients currently taking oral hypoglycaemic agents was included. The glycaemic control was reflected by the level of hemoglobin A1c (HbA1c) taken within the previous 6 months. Factors associated with poor glycaemic control (HbA1c ≥ 7.0%) were evaluated by linear regression analysis. From 565 eligible Chinese patients with an average age of 63.2 years (SD 9.7) and male proportion of 46.5%, the average HbA1c was 7.1% (SD 1.1%), and 52.0% had poor glycaemic control. The proportion of poor medication adherence (MMAS-8 ≤ 6) was 32.2%. After controlling for socio-demographics, lifestyle, medication use, and health characteristics, the MMAS-8 score was correlated with better glycaemic control (beta −0.095; 95%CI −0.164 to −0.026, P = .007). The MMAS-8 score had a weak and negative correlation with HbA1c level. The instrument should be applied with caution when predicting glycaemic control in clinical practice