AN ECONOMIC-ANALYSIS OF CAPTOPRIL IN THE TREATMENT OF DIABETIC NEPHROPATHY

OBJECTIVE - The results of a recent clinical trial, The Effect of ACE inhibition on Diabetic Nephropathy, demonstrated that captopril reduce d the rate of renal failure, end-stage renal disease (ESRD), and death in patients with IDDM and nephropathy. The purpose of this study was to determine the cost-benefit and cost-effectiveness of captopril as a therapy in patients with IDDM as well as the potential savings for al l patients with diabetes and nephropathy. RESEARCH DESIGN AND METHODS - We used the results from a randomized, placebo-controlled trial comp aring captopril (207 patients) with placebo (202 patients), whose purp ose was to determine whether captopril has kidney-protecting propertie s independent of its effect on blood pressure in diabetic nephropathy to develop a model of medical treatment for patients before progressio n to ESRD. To model the course of illness after progression to ESRD an d to extend the model to patients with NIDDM, we used data from the U. S. Renal Data System and published literature. Medical resource cost d ata were based predominantly upon Medicare reimbursement levels, publi shed wholesale drug prices, and surveying health care providers. The e conomic model uses a payer perspective to estimate direct cost. The co st to society (indirect cost) associated with lost patient productivit y due to ESRD was also estimated. Using this information, we predicted the costs incurred annually and over a lifetime if patients with IDDM and NIDDM and overt nephropathy were treated with either placebo or c aptopril. We also constructed a model of the overall prevalence of dia betic nephropathy to estimate the aggregate savings in total U.S. heal th care expenditures. RESULTS - Treatment with captopril resulted in a n absolute direct cost savings or benefit of $32,550 per patient with IDDM over the course of a lifetime compared to treatment with placebo. For patients with NIDDM, the direct cost savings totaled $9,900 per p atient. Absolute savings were found for indirect costs as well: $84,39 0 per patient with IDDM and $45,730 per patient with NIDDM. If captopr il therapy were initiated in 1995 for patients with either IDDM or NID DM and nephropathy, the aggregate health care cost savings (i.e., dire ct cost savings alone) mould be $189 million a year for the year 1999 and $475 million a year in 2004; the present value of cumulative healt h care cost savings for these 10 years would be $2.4 billion. CONCLUSI ONS - The use of captopril in diabetic nephropathy will provide signif icant savings in health care costs; in addition, it will result in sav ings in indirect cost, which reflects the broader societal benefit.