OBJECTIVES : To evaluate the HbA1c control state, diabetic complications occurrence rate in type 2 diabetes mellitus (T2DM) patients whose hypoglycemic regimens maintained for at least 1 year and analyze the cost-effectiveness of different drugs in these patients.

METHODS : A retrospective study was conducted focused on T2DM patients with the state of abnormal maintenance of their hypoglycemic regimens. Forty patients who were definitively diagnosed T2DM in Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital were screened every month from 2012 to 2016. Patients (i)without liver or kidney dysfunction, (ii) failed to visit medical institutions and adjust hypoglycemic regimens within last 12 months (except for drugstore) were included. Strictly verification by telephone was conducted to ensure the accuracy of the collected data. The whole process was executed by two investigators (WXW and GL) back to back. Patients’ medication drugs, costs, HbA1c test results and complications were collected. We used Cost*HbA1c (/Yuan*%) to evaluate the cost-effectiveness status of drugs accepted by these patients. The effects of duration of hypoglycemic regimen maintain and other covariates on blood glucose under control rate, Cost*HbA1c and complications were analyzed.

RESULTS : Totally 167 of 2400 patients were selected, and 8 anti-diabetic agents were analyzed. With the maintenance of hypoglycemic regimen increased from 1year-2years to more than 3years, HbA1c under control rate dropped from 33.3% to 12.5% and each of the occurrence rate of five kinds of diabetic complications (nephropathy, peripheral neuropathy, vascular disease, diabetic oculopathy and ketoacidosis) was significantly increased (P<0.0001). Multiple linear regression analysis showed that the use of 8 drugs were significantly influence Cost*HbA1c. Metformin had a smallest standardized estimate (P <0.0001) which indicated the best cost-effectiveness characteristic.

CONCLUSIONS : Long time unchanged hypoglycemic regimen may lead to poor HbA1c control rate and more complications. And Metformin may be the medicine with the best cost-effectiveness characteristic.