Cost effectiveness of ramipril in patients at high risk for cardiovascular events : economic evaluation of the HOPE (Heart Outcomes Prevention Evaluation) study for Germany from the Statutory Health Insurance perspective

Abstract

Background: In the HOPE (Heart Outcomes Prevention Evaluation) trial, ramipril (compared with placebo) significantly reduced cardiovascular death and all-cause mortality as well as the incidence of costly cardiovascular events, such as myocardial infarction, revascularisation, stroke, cardiac arrest, hospitalisation due to heart failure and worsening angina pectoris, new-onset diabetes mellitus and microvascular diabetic complications.

Objective: Data from the HOPE study were used in a cost-effectiveness analysis to determine the additional cost per life-year gained (LYG) when the ACE inhibitor ramipril was added to the current medication of patients at high risk for cardiovascular events. The aim was to establish the incremental cost-effectiveness ratio (ICER) of ramipril versus placebo from the perspective of the Statutory Health Insurance (SHI) provider in Germany, for both the study population as a whole and for the subgroup of patients with diabetes.

Design: A modelling approach was used, based on secondary analysis of published data and retrospective application of costs. In the base-case analysis, average case-related expenses of the SHI were applied and LYG were quantified using the average of the difference between the survival rates in the ramipril and placebo groups during the HOPE trial. LYG beyond the trial duration were estimated by the method of declining exponential approximation of life expectancy.

Results: After a treatment period of 4.5 years, the ICER of ramipril versus placebo was Euros 4074/LYG and Euros 2486/LYG (discounted at 5% per annum and in 1998-2002 values; Euro 1 approximately USD 0.88; first quarter 2002 values) for the HOPE study population as a whole and the subgroup of patients with diabetes, respectively. To test the model's robustness, the influence of the model variables on the results was quantified using a deterministic model, and a best-case/worst-case scenario analysis. The effect of random variables was investigated in a Monte Carlo simulation. The acquisition cost for ramipril had the greatest impact on the ICER of ramipril (2.2-fold greater than the impact of the number of LYG). In 95% of the 10,000 simulation steps, the ICER of ramipril after 4.5 years of treatment was between Euros 1290 and Euros 9005 per LYG for the entire HOPE study population and between Euros 290 and Euros 6115 per LYG in the diabetic subgroup.

Conclusions: Results of this evaluation suggest that ramipril is likely to be cost effective in secondary prevention of cardiovascular events from the perspective of the SHI (third-party payer) in Germany. The estimated ICER of ramipril compares well with other ICERs of widely accepted treatments used for the management of cardiovascular diseases, such as HMG-CoA reductase inhibitors.