To evaluate the reliability and validity of the Chinese version of the 8-item Morisky medication adherence scale (MMAS-8) in patients with type 2 diabetes and to explore the influence of different factors on patient medication compliance.

We used the Chinese version of MMAS-8 and MMAS-4 to survey 148 type 2 diabetes patients who were treated at the First Affiliated Hospital of Kunming Medical University from July 2014 to January 2015. For the Chinese version of MMAS-8, we used Cronbach′s alpha to evaluate its internal consistency reliability, and intra-group correlation coefficient (ICC) to evaluate the test-retest reliability; we also used principal component factor analysis to evaluate construct validity and Spearman correlation coefficient to evaluate the convergent validity.Two independent sample t-tests were used to compare the scores of the Chinese version of MMAS-8 in patients with good glycemic control and those with poor glycemic control, and the chi-square test was used to compare the distribution of drug adherence in patients with good glycemic control and those with poor glycemic control, in order to evaluate discriminant validity of the Chinese version of MMAS-8. Multivariate logistic regression analysis was used to analyze the influencing factors of drug adherence in type 2 diabetes patients.

The Cronbach′s alpha of the Chinese version of the MMAS-8 was 0.776, and the ICC was 0.854 (P<0.05). Principal component factor analysis extracted three common factors. The correlation coefficient between the MMAS-8 and MMAS-4 was 0.878 (P<0.001). The MMAS-8 score was significantly higher in patients with good glycemic control (HbA1c<7%) than in those with poor glycemic control (HbA1c≥7%) [(7.20±1.04) vs (5.94±2.03), t=3.910, P<0.001], and the distribution of patients with different compliance also differed significantly between the two groups (χ²=14.554, P=0.010). Multivariate logistic regression analysis showed that men compared to women (OR=0.405, 95%CI=0.197-0.829, P=0.013), medical insurance for urban workers compared to self-paying (OR=0.130, 95%CI=0.021-0.800, P=0.028), and monotherapy compared to multi-drug treatment (OR=2.970, 95%CI=1.499-5.882, P=0.002) had a significant effect on medication adherence. Age, course of disease, education, occupation, body mass index, complications, and insulin treatment had no significant effect on medication compliance (P>0.05).

The Chinese version of the MMAS-8 has good reliability and validity. The medication adherence of patients with type 2 diabetes is associated with gender, the type of medical insurance, and hypoglycemic therapy.