Cost-effectiveness of the use of the continuous subcutaneous insulin infusion pump versus daily multiple injections in type 1 diabetes adult patients at the Mexican Institute of Social Security

BACKGROUND: To estimate the incremental cost-effectiveness ratio (ICER) of the use of continuous subcutaneous insulin infusion (CSII) therapy versus multiple daily injections (MDI) therapy in adult patients with type 1 diabetes (T1D) at the Mexican Institute of Social Security (IMSS). METHODS: An analysis was developed using the internationally validated Core Diabetes Model (CDM) with which the incidence and progression of acute and chronic complications and the mortality of T1D was simulated throughout life. The baseline characteristics of the simulated cohorts were obtained from Mexican T1D adult patients aged ≥ 18 years that received care at two national IMSS medical centres in 2016. In the base case, the costs of the complications and treatment of the disease with both therapies were estimated in Mexican currency from the perspective of the institution, using Diagnosis Related Groups for outpatient and inpatient care. Utilities were taken from the international bibliography. In a secondary analysis, indirect costs were included using a human capital approach. The model used a lifetime time horizon, and a discount rate of 5% was applied for health outcomes and costs. A one-way sensitivity analysis was conducted on key variables and patient sub-groups; uncertainty was evaluated using a Cost-Effectiveness Acceptability Curve. RESULTS: The average age of the cohort was 32 years, with diabetes duration of 19 years, an average HbA1c of 9.2%; 29% were men. A gain of 0.614 Quality Adjusted Life Years (QALYs) was estimated with the use of CSII therapy. The estimated ICER was MXN$478,020 per QALY in the base case, and MXN$369,593 when indirect costs were considered. The sensitivity analysis showed that, in adult patients with HbA1c > 9.0%, the ICER was MXN$262,237. CONCLUSIONS: This is the first economic evaluation study that compares CSII therapy versus MDI therapy for T1D adult patients in Mexico. The insulin pump therapy can be considered cost-effective in the context of the IMSS when considering a threshold of three GDPs per capita with 43.9% probability. Results improve substantially when patients have an HbA1c above 9%.