Cost-effectiveness study of oral hypoglycemic agents in the treatment of outpatients with type 2 diabetes attending a public primary care clinic in Mexico City

INTRODUCTION Worldwide, diabetes mellitus presents a high burden for individuals and society. In Latin America, many people with diabetes have limited access to health care, which means that indirect costs may exceed direct health care cost. Diabetes is Mexico's leading cause of death. PURPOSE To evaluate the cost-effectiveness ratios of the most used oral hypoglycemic agents (OHA) in the treatment of outpatients with type 2 diabetes attending a public primary care clinic in Mexico City. DESIGN A cross-sectional and analytic study was conducted in Mexico City. METHODOLOGY Twenty-seven adult outpatients with type 2 diabetes who were treated either with metformin or glibenclamide were included. Acarbose was used as an alternative strategy. The study was carried out from the perspective of Mexican society. Direct medical and nonmedical costs as well as indirect costs were evaluated using a structured questionnaire. Efficacies of all drug treatments were evaluated retrospectively. A systematic search was conducted to select published randomized clinical trials based on predetermined inclusion criteria, and treatment success was defined as glycosylated hemoglobin factor ≤ 7%. Efficacy data of each drug and/or combination were analyzed using meta-analysis. The Monte Carlo Markov model was used. Quality-adjusted life-years (QALY) were used as the unit of effectiveness; incremental and sensitive analyses were performed and a 5% discount rate was calculated. A hypothetical cohort of 10,000 patients was modeled. RESULTS The odds ratios of the success of each drug treatment were obtained from the meta-analyses, and were the following: 5.82 (glibenclamide), 3.86 (metformin), 3.5 (acarbose), and 6.76 (metformin-glibenclamide). The cost-effectiveness ratios found were US$272.63/QALY (glibenclamide), US$296.48/QALY (metformin), and US$409.86/QALY (acarbose). Sensitivity analysis did not show changes for the most cost-effective therapy when the effectiveness probabilities or treatment costs were modified. CONCLUSION Glibenclamide is the most cost-effective treatment for the present study outpatient population diagnosed with type 2 diabetes in the early stages.