A French cost-consequence analysis of the renoprotective benefits of irbesartan in patients with type 2 diabetes and hypertension.

OBJECTIVES

We performed a cost-consequence analysis in a French setting of the renoprotective benefit of irbesartan in hypertensive type 2 diabetes patients over a 25-year period.

RESEARCH DESIGN AND METHODS

A previously published Markov model simulated progression from microalbuminuria to overt nephropathy, doubling of serum creatinine, end-stage renal disease and death. Three treatment strategies with analogous blood pressure control were compared: (A) control--conventionally medicated antihypertensive therapy (excluding angiotensin converting enzyme inhibitors, other angiotensin-2-receptor antagonists and dihydropyridine calcium channel blockers) initiated at microalbuminuria; (B) early irbesartan--(300 mg daily added to control, initiated with microalbuminuria) and (C) late irbesartan--(300 mg daily, initiated with overt nephropathy). Probabilities came from the Irbesartan in Reduction of Microalbuminuria-2 study, Irbesartan in Diabetic Nephropathy Trial and other sources. Clinical and economic outcomes were projected over 25 years. Annual discount rates were 3%.

RESULTS

Compared to control, early use of irbesartan added (mean +/- standard deviation) 1.51 +/- 0.08 undiscounted life years (discounted: 0.94 +/- 0.05 years), while late irbesartan added 0.07 +/- 0.01 (0.04 +/- 0.01) years/patient. Early irbesartan added 1.03 +/- 0.06 discounted quality-adjusted life years (QALYs), while late irbesartan added 0.06 +/- 0.01 QALYs. Early and late irbesartan treatments were projected to save 22,314 +/- 1273 euro and 6619 +/- 820 euro/patient, respectively versus control. Sensitivity analysis showed that even over short time horizons both irbesartan treatments were superior to the control group.

CONCLUSIONS

In France, early irbesartan treatment improved quality and length of life and reduced costs in hypertensive patients with type 2 diabetes and microalbuminuria. Late irbesartan therapy is beneficial, but earlier irbesartan leads to better outcomes.