Objective Our aim was to apply Markov model to the Pharmacoeconomic evaluation of the effect with long-term low doses of amlodipine plus amiloride or telmisartan antihypertensive therapy, to provide a basis for the selection of optimised combination therapy, to offer the methodological reference for the Pharmacoeconomic evaluation of the domestic hypertension Intervention.

Methods 1. According to the natural history of hypertension, Markov model was constructed to simulate the dynamic changes of the five states (event free, non-fatal myocardial infarction, non-fatal stroke, natural death and non-natural death) in the hypertension patients who received the two combined treatment, and a 1-year cycle length was chosen. 2. We had applied Markov model using Roll back analysis, Markov cohort simulation and Monte Carlo simulation analysis to project expected life years, the expected quality-adjusted life years and the medical costs in the subsequent 40 yrs of life time for the hypertension patients who had been long-term treated with low dose of amlodipine plus amiloride or telmisartan. Sensitivity analysis were carried out to determine the robustness of our baseline results. 3. On the basis of the published study of China's population-based clinical trials, we had obtained Markov model transition probability between states, health utility values and health care costs in the states through literature review and search statistical data of China.

Results 1. The baseline Roll back analysis showed that after amlodipine plus amiloride antihypertensive therapy for 40 years, the average cost-effectiveness ratio was 1416 yuan/QALY and 1790 yuan/QALY respectively. According to Monte Carlo simulation analysis, the average cost-effectiveness ratio of the amlodipine plus amiloride treatment and its 95% CI were 1173.1 yuan/QALY (95% CI 1139.43 yuan/QALY to 1174.72 yuan/QALY). 2. The baseline Roll back analysis after amlodipine plus telmisartan antihypertensive therapy for 40 years showed that the average cost-effectiveness ratio was 2252 yuan/LYG and 2334 yuan/QALY respectively. According to Monte Carlo simulation analysis, the average cost-effectiveness ratio of the amlodipine plus telmisartan treatment and its 95% CI were 1843.6 yuan/QALY (95% CI 1, 817.15 yuan/QALY 1850.00 yuan/QALY). 3. Compared with amlodipine plus amiloride antihypertensive therapy, the incremental cost-effectiveness ratio of telmisartan plus amlodipine treatment was 75713 yuan/QALY. The incremental net monetary benefit and the incremental net health benefit were −7480.1 yuan (95% CI −7804.6 to −7155.6 yuan) and −0.329QALYs (95 % CI −0.343 QALYs to −0.315 QALYs), which used the 2008 per capita GDP 22698 yuan as the threshold. The probability that the net benefits of the Amlodipine plus amiloride treatment was greater than that of telmisartan plus amlodipine treatment was 94.5%. 4. According to the sensitivity analysis, the change of key parameters in the set range did not affect the model results.

Conclusion 1. Two combination regimens were able to attain significant clinical effectiveness and economic Benefit, however in the case of limited resources, priority should be given to the amlodipine plus amiloride combined antihypertensive therapy as the initial program, in order to obtain better economic benefit. 2. Markov model can be good used for Economic evaluation of blood pressure intervention.