BACKGROUND: Adverse drug reactions and medication nonadherence are well-known causes of sub-optimal disease control and worsened disease outcomes in patients who are treated for type 2 diabetes. Metformin sustained release (SR) might reduce these adverse events and improve medication adherence via a simplified treatment regimen for metformin immediate release (IR)-intolerant patients.
OBJECTIVES: The aim of this study is to estimate the budget impact of metformin SR for the treatment of type 2 diabetes in the Netherlands, compared to the current standard of care (SoC) with metformin IR.
METHODS: A budget impact model was built to represent the course of the disease and treatment pathway of type 2 diabetes patients eligible for metformin SR from a healthcare payer's perspective. Patients were considered eligible if they used less than 2000 mg metformin IR per day, but suffered from adverse events that might lead to therapy discontinuation, and if they were newly diagnosed with type 2 diabetes. The costs of type 2 diabetes treatment and related complications over a time horizon of 3 years were calculated. Univariate sensitivity analyses were conducted to show which parameters have the biggest influence on the budget impact.
RESULTS: The budget impact analysis showed cost-savings of - €1,962,335 over a period of 3 years through implementation of metformin SR as an alternative to SoC with metformin IR. Savings were mostly driven by the delay of other, more expensive type 2 diabetes treatments, such as insulin. In sensitivity analyses, medication adherence and persistence appeared to have the biggest influence on the budget impact.
CONCLUSION: Metformin SR could potentially be a cost-saving alternative to metformin IR for the treatment of type 2 diabetes in the Netherlands, especially in patients experiencing adverse events with metformin IR. However, more research is needed to better predict the effect of using once-daily metformin, compared to multiple dosages, on medication adherence and persistence and to evaluate whether metformin SR really decreases the amount of adverse events.