Cost effectiveness of ramipril in patients with non-diabetic nephropathy and hypertension - Economic evaluation of Ramipril Efficacy In Nephropathy (REIN) study for Germany from the perspective of statutory health insurance

Background: In the Ramipril Efficacy in Nephropathy (REIN) trial, ramipril significantly lowered the rate of reaching the combined end-point of doubli ng of baseline serum creatinine levels or end-stage renal failure (ESRF). Objective: To determine the additional cost per patient-year of chronic (lo ng term) dialysis avoided (PYCDA) when the ACE inhibitor, ramipril, was add ed to conventional treatment of patients with non-diabetic nephropathy and hypertension. Study perspective: Statutory Health Insurance (SHI) provider in Germany. Design and setting: Data from the REIN Study were used in a cost-effectiven ess analysis (CEA). A modelling approach was used, which was based on secon dary analysis of published data, and costs were those incurred by the SHI p rovider (i.e. SHI expenses). In the base-case analysis, average case-relate d SHI expenses were applied and PYCDA were quantified using the cumulative incidence of ESRF as observed in the REIN trial. Main outcome measures and results: The incremental cost-effectiveness ratio s (ICERs) of ramipril varied between about -76 700 deutschmarks (DM) and -D M81 900 per PYCDA (DM1 approximate to 0.55 US dollars; 1999 values), accord ing to the treatment periods of I year and 3 years, respectively. In the se nsitivity analysis, the robustness of the model and its results were shown when the extent of influence of different model variables on the base-case results was investigated. First, probabilities of ESRF and PYCDA were estim ated according to the Weibull method. Second, the influence of the model va riables on the target variable was quantified using a deterministic model. Third, the dependency of the target variable (ICER) on random variables was described in a simulation. The cost for chronic dialysis had by far the gr eatest impact on the target variable, which was 28 times greater than the i mpact of clinical effectiveness of ramipril, i.e. the number of PYCDA. Ther e were net savings per PYCDA with ramipril treatment after 1, 2 and 3 years : 95% of the 10 000 simulation steps resulted in savings of between DM69 50 0 and DM94 600 per PYCDA after 3 years. Conclusions: Results from this evaluation show that ramipril offers enormou s savings from the perspective of the SHI provider (third-party payer) in G ermany when added to the conventional treatment of patients with non-diabet ic nephropathy and hypertension.