Economic evaluation of irbesartan in combination with hydrochlorothiazide in the treatment of hypertension in Greece.

objectivesHypertension is a major risk factor for cardiovascular disease and a leading cause of morbidity and mortality. This study evaluates irbesartan in relation to commonly used alternative hypertension therapies losartan and valsartan given in combination with hydrochlorothiazide (HCTZ) in the general hypertensive population in Greece.

methodsA Markov model with eight states of health was constructed: hypertension, myocardial infarction (MI), post-MI, angina, stroke, poststroke, heart failure, and death. The model has an annual cycle and estimates mean quality-adjusted survival and treatment cost, which reflect the hypertension treatment and managing cardiovascular events. Risk functions were used to conduct extrapolations. Data on treatment effectiveness, quality of life (QOL) and epidemiology were obtained from published clinical trials and studies. The database of the main Greek National Social Insurance Institute (IKA) was analyzed to estimate the cost of events. The analysis was done from a payer perspective. All outcomes were discounted, and prices correspond to 2008.

resultsThe estimated patient cost per annum was stable angina euro 2,252, unstable angina euro 2,572, myocardial infarction euro 2,473, post-MI euro 1,677, stroke euro 12,233, poststroke euro 1,240, heart failure euro 2,655, coronary angiography euro 1,544, percutaneous transluminal coronary angioplasty euro 6,511, and coronary artery bypass graft surgery euro 11,514. For the baseline group (age 57 years, systolic blood pressure 147 mmHg, cholesterol 6.00 mmol/L, body mass index 29) of men with mild to moderate hypertension, for irbesartan, the total treatment cost was euro 15,146, for losartan euro 15,696 and for valsartan euro 15,613; the quality-adjusted life years (QALYs) were irbesartan 12.67, losartan 12.63 and valsartan 12.64. For the baseline group of women with mild to moderate hypertension, the total treatment cost was euro 12,945 for irbesartan, euro 13,424 for losartan and euro 13,379 for valsartan; QALYs were 14.29 for irbesartan, 14.27 for losartan and 14.27 for valsartan. For men with severe hypertension, for irbesartan and losartan, the total treatment cost was euro 18,679 and euro 21,488 and QALYs 12.47 and 12.37, respectively. For women, the total treatment cost was euro 16,202 and euro 19,099 and QALYs 14.16 and 14.09, respectively. Similar results were obtained in relation to other treatment groups in various sensitivity analysis scenarios.

conclusionsBased on efficacy data from clinical trials and lower attainment costs in various hypertensive patient populations, irbesartan in combination with HCTZ compares favorably with losartan and valsartan in combination with HCTZ in the Greek setting.