Cost-effectiveness analysis of ramipril in heart failure after myocardial infarction. Economic evaluation of the Acute Infarction Ramipril Efficacy (AIRE) study for Germany from the perspective of Statutory Health Insurance

Abstract

Objective: Data from the Acute Infarction Ramipril Efficacy (AIRE) study were used in a cost-effectiveness analysis to determine the incremental cost per life-year gained (LYG) when the ACE inhibitor ramipril was added to conventional treatment in patients with heart failure after acute myocardial infarction. In the AIRE trial, the addition of ramipril significantly lowered rates of total mortality and rehospitalisation due to heart failure.

Design and setting: The cost-effectiveness analysis was conducted from the perspective of the Statutory Health Insurance (SHI) provider in Germany. A modelling approach was used which was based on secondary analysis of existing data, and costs were those incurred by SHI (i.e. expenses of SHI). In the base-case analysis, average case-related expenses of SHI were applied and LYG were quantified by the method of Kaplan and Meier.

Main outcome measures and results: The incremental cost-effectiveness ratios of ramipril varied between 2500 and 8300 deutschmarks (DM) per LYG (1993 values for inpatient and 1995 values for outpatient treatment; DM1 approximately $US0.70), according to the treatment periods of 3.8 years and 1 year, respectively. In the sensitivity analysis, the robustness of the model and its results was shown when the extent of influence of different model variables on the base-case results was investigated. First, survival probability and LYG were estimated according to the Weibull method. Second, the dependency of the target variable (i.e. incremental cost per LYG) on random variables was described in a simulation. Third, the influence of the model variables on the target variable was quantified using a deterministic model. The variance of the target variable was broad and the hospitalisation impact of adding ramipril to conventional treatment was an independent variable with much greater influence on the target variable than the parameter of clinical effectiveness, i.e. the number of LYG.

Conclusion: Results of this evaluation showed that ramipril has a favourable incremental cost-effectiveness ratio for the treatment of heart failure in post myocardial infarction patients and can be considered an economical therapeutic agent from the perspective of SHI (third-party payer) in Germany.