The cost-effectiveness of irbesartan in the treatment of hypertensive patients with type 2 diabetic nephropathy

Background: End-stage renal disease (ESRD)-related health care costs are substantial. Improving clinical outcomes in patients at risk of progression to ESRD could lead to considerable health care savings. Objective: We estimated the cost-effectiveness of irbesartan compared with placebo or amlodipine in the treatment of patients with type 2 diabetes mellitus, hypertension, and overt nephropathy. Methods: Three treatments for hypertensive patients with type 2 diabetes mellitus and nephropathy were assessed: (1) irbesartan, (2) amlodipine, and (3) placebo. A Markov model was developed based on primary data from the Irbesartan in Diabetic Nephropathy Trial and the United States Renal Data System. Projected survival and costs were compared for each treatment at 3-, 10-, and 25-year time horizons. Different assumptions of treatment benefits and costs were tested with use of sensitivity analyses. Results: At 10 and 25 years, the model projected irbesartan to be both the least costly and most effective (ie, demonstrating a survival advantage) strategy. At 25 years, the model predicted a mean gain of 8.9 and 7.5 months of life, with cost savings of $15,607 and $26,290 per patient with irbesartan versus placebo and amlodipine, respectively. At year 3, minimal differences in life expectancy were observed. The model projected a gain of 6.3 days of life and cost savings of $2778 per patient in favor of irbesartan versus placebo; a 1.5-day gain in favor of amlodipine versus irbesartan was achieved at an added cost of $4217 per patient (incremental cost-effectiveness ratio of $1,047,533 per life-year saved). These results were consistent under a wide range of sensitivity analyses. Conclusion: This Markov model predicted that irbesartan would increase life expectancy and decrease costs of care in patients with type 2 diabetic nephropathy. Based on these results, irbesartan could have the potential to substantially reduce the clinical and economic burdens of patients with type 2 diabetic nephropathy. Copyright © 2003 Excerpta Medica, Inc.