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 EURO22 314 +/- 1273 and EURO6619 +/- 820/ 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.