OBJECTIVES: To examine the trends of outpatient medication adherence among type 2 diabetes in China.

METHODS: Cohort data from chronic disease management database and health insurance claim database in an eastern provincial capital city of China was used. We identified individuals diagnosed with type 2 diabetes in 2014 as target population and tracked their drug used records in the year of 2014, 2016 and 2019. Medication adherence was measured by proportion of days covered (PDC) at individual level, calculated as the sum of maximum days covered by drugs in each prescription divided by 365 days. PDC≥0.8 was defined as high medication adherence. Descriptive analysis and statistical test were employed to demonstrate the trends of medication adherence.

RESULTS: A total of 20,742 diabetes patients were included in this study with average age of 67.91 years old. As for the drug use pattern, 40.95% of patients used two types of drugs for diabetes in 2014, while this share decreased to 35.06% in 2019. Following that, 28.71% of patients used only one type of diabetes drug in 2014, while this figure reduced to 19.76% in 2019. The three types of drugs most commonly prescribed were insulin, sulfonylureas and glucosidase inhibitor, with number of prescriptions per capita as 10.24, 8.39 and 8.17 respectively in 2019. The average outpatient PDC among diabetes patients was 0.69±0.30, 0.80±0.25 and 0.81±0.27 in the year of 2014, 2016, and 2019 respectively, reflecting a rising trend (P<0.01). The proportion of patients with high medication adherence in 2014, 2016, and 2019 was 44.75%, 61.19%, 67.46%, revealing a significant increase (P<0.01).

CONCLUSIONS: The overall medication adherence among diabetes patients was improving during recent years while more efforts should still be made to elevate the level to be high adherence.