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.

Background: Adherence with oral hypoglycaemic agent is important to achieve optimal glycaemic control. The eight-item Morisky Medication Adherence Scale (MMAS-8) is frequently used for measuring drug adherence, yet the association between MMAS-8 score and glycaemic control among diabetes patients has not been addressed. Methods: Two general outpatient clinics were randomly selected in a district with socio-demographic representative of the entire Hong Kong population. In 2013, all type II adult diabetes patients on oral hypoglycaemic agents were consecutively invited to participate in a self-administered survey with the validated Chinese version of MMAS-8. The glycaemic control was reflected by HbA1c taken in the clinic in the same occasion. Factors associated with poor glycaemic control (HbA1c ≥ 7.0%) were explored by a binary logistic regression analysis. Results: 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 7.14% (SD 1.1%), and 48.0% [271/565] had poor glycaemic control (HbA1c ≥ 7.0%). The proportion of poor medication adherence (MMAS-8≤ 6) was 32.2% [182/565]. After controlling for age, sex, education level, BMI, income, smoking, alcohol drinking, compliance with diabetes diet, and use of chronic medications (antihypertensive agents; lipid-lowering agents; antiplatelets), the higher MMAS-8 score (better drug adherence) was significantly associated with HbA1c level (Beta -0.115; 95% C.I. -0.164 to -0.026, p = 0.007). Conclusion: The MMAS-8 score was negatively correlated with HbA1c, further strengthening its validity in prediction of glycaemic control among diabetes patients.