[Clinical and health economic implications of early treatment with irbesartan of patients with type 2 diabetes mellitus, hypertension and nephropathy]

Abstract

Background and objective: It was the aim of this study to project the long-term clinical and cost outcomes of irbesartan treatment, based on data from the irbesartan in Reduction of Microalbuminuria-2 (IRMA-2) study and the irbesartan in Diabetic Nephropathy Trial (IDNT), in hypertensive patients with type 2 diabetes and renal disease in Germany.

Patients and methods: A Markov model adapted to the German setting simulated progression of renal disease and associated changes in mortality in patients with hypertension, type 2 diabetes and microalbuminuria. Early irbesartan 300 mg daily (initiated at microalbuminuria) and late irbesartan (initiated at overt nephropathy) were compared to a control scheme of antihypertensive standard medications with comparable blood pressure control, initiated at microalbuminuria. Cumulative incidence of ESRD, time to onset of ESRD, life expectancy (LE), quality-adjusted life years (QALY) and costs were projected over 25 years for 1,000 simulated patients, from a third party payer perspective. Clinical and cost outcomes were discounted at 5% per annum.

Results: When compared to standard blood pressure control, both early and late treatment with irbesartan were projected to reduce the cumulative incidence of ESRD fromm23.80.3% to 9.10.6% and 19.83%, increase discounted LE by 0.670.04 and 0.030.00 years, and improve QALY by 0.750.04 and 0.070.01 years per treated patient, respectively. Early irbesartan treatment was associated with a cost savings of i 12,658825 per patient while late irbesartan treatment was associated with a cost savings of i 4,116575 per patient compared to control over the 25-year time horizon.

Conclusions: Early irbesartan treatment was projected to improve LE and QALY, and reduce the onset of ESRD, with cost savings, in hypertensive patients with type 2 diabetes and microalbuminuria in Germany. Later use of irbesartan in overt nephropathy is also superior to standard care. These findings suggest that irbesartan should be started earlier and continued long-term.