COST-UTILITY ANALYSIS OF THE COMBINED THERAPY OF DIABETES MELLITUS TYPE 2 USING SENSITIVITY ANALYSIS

Aim. Pharmacoeconomical research of drug regimens of diabetes mellitus (DM) type 2 was conducted with the purpose of definition of the pharmacoeconomically justified schemes of therapy based on cost-utility analysis. Subjects: 100 questionnaires to determine the quality of life of patients with DM type 2. In-patients were treated in specialized hospitals of Podolsky region (Vinnytsia regional endocrinology clinic, endocrinological departments of the Khmelnytsky and Ternopil regional hospitals) in 2011-2013. The quality of life of patients was determined by visual analogue scale (VAS) of the adapted European questionnaire of quality of life. This method is based on self-assessment of the patients' status from the worst (0%) to the best (100%) state. Material and Methods. Retrospective analysis of 1792 medical histories and treatment sheets, frequency analysis of the treatment regimens, sociological survey using VAS, ATC/DDDanalysis, cost-utility analysis based on minimal and maximal prices of oral hypoglycemic drugs at the regional pharmaceutical market, and sensitivity analysis to identify the stability of the pharmacoeconomic research results. Results and Discussion. Ñombined second-line treatment regimens with metformin+glimepiride and metformin+ gliclazide are used most frequently. These treatment regimens were selected for cost-utility analysis. It has been found that the cost of DDD of metformin+glimepiride regimen is ranged from 2,70 UAH tî 8,88 UAH, metformin+gliclazide regimen - from 3,29 UAH tî 9,43 UAH. It has been found that the quality of life was 0,69±0,02 for patients with treatment regimen metformin+glimepiride, and 0,65±0,02 - for patients with metformin+gliclazide treatment regimen. It was found that the number of quality-adjusted life years (QALYs) for scheme of pharmacotherapy with metformin+glimepiride was 9,76 QALYs, and for scheme of pharmacotherapy with metformin+gliclazide - 8,66 QALYs. The cost of 1 QALY for metformin+glimepiride scheme is ranged from 1427,76 UAH to 4695,76 UAH, and metformin+gliclazide scheme - from 1847,03 UAH to 5294,08 UAH in the context of cost of generics. Univariate sensitivity analysis showed that treatment regimens with metformin + glimepiride has cost-beneficial advantages in increase of the value up to 37%, but with the further increase in the cost the pharmacoeconomic benefits of this scheme are lost. Two-factor sensitivity analysis found that treatment regimen with metformin+glimepiride has cost-beneficial advantages in elevation of the value up to 17% and in reduction of efficiency up to 17%, and in case of further increase in price and decline in the efficiency the pharmacoeconomic benefits of this treatment regimens are lost. Conclusions. We have found that the scheme of pharmacotherapy with metformin+glimepiride was cheaper and more beneficial in comparison with scheme of pharmacotherapy with metformin+gliclazide considering minimal and maximal prices of the generics. The sensitivity analysis showed the stability of the results of the pharmacoeconomic study against fluctuations in the value of DDD up to 37% and synchronous changes of the DDD value and efficiency - up to 17%. Keywords: diabetes mellitus, quality of life, cost utility analysis