Antihypertensive treatment with and without benazepril in patients with chronic renal insufficiency - A US economic evaluation

Objective: To conduct an economic analysis in the US of antihypertensive treatment with and without benazepril in patients with chronic renal insufficiency. Design: A four-state Markov model, using clinical data obtained from a 3-year randomised clinical trial [the Angiotensin-Converting-Enzyme Inhibition in Progressive Renal Insufficiency (AIPRI) study] plus its extension study (median 3.6 years), and cost data obtained from published US sources. The period of analysis was 7 years following randomisation. Perspective: Healthcare payer. Setting: Clinical data were obtained from multiple medical centres in three European countries as described in the published studies. Key economic data were obtained from the US Healthcare Financing Administration's End Stage Renal Disease programme. Patients and interventions: In the clinical studies on which this economic analysis was based, patients with chronic renal insufficiency of various aetiologies were randomised to antihypertensive therapy with or without concomitant benazepril. Main outcome measures and results: Over 7 years of analysis, patients randomised to antihypertensive treatment with concomitant benazepril therapy incurred on average $US 12 991 (1999 values) lower medical costs than patients prescribed antihypertensive treatment without benazepril, and obtained an additional 0.091 quality-adjusted life years (QALYs). Costs and QALYs were greater for the benazepril arm than the placebo arm for all years of analysis after the first. Rank order stability of results favouring the benazepril therapy arm was found in sensitivity analyses of changes in key model parameters. Additional economic and health benefits favouring patients receiving benazepril would be seen if underlying model rates of dialysis and transplantation were increased, as may be appropriate to reflect treatment practice differences in the US relative to European countries. Conclusions: Benazepril therapy as a component of antihypertensive treatment of persons with chronic renal insufficiency initially costs money, but investment costs are recouped quickly and return on investment continues to grow. The impact of end-stage renal disease on patient health and healthcare costs is great. Thus, the quality-adjusted survival benefits and overall cost savings seen in benazepril recipients over a prolonged period (2 to 7 years) indicate that the strategy of prescribing benazepril to reduce progression of renal disease in patients with renal insufficiency is both clinically and economically beneficial compared with current antihypertensive regimens without ACE inhibition.