Cost-utility analysis of antihypertensive medications in Nigeria: a decision analysis

BACKGROUND: Many drugs are available for control of hypertension and its sequels in Nigeria but some are not affordable for majority of the populace. This serious pharmacoeconomic question has to be answered by the nation's health economists. The objective of this study was to evaluate the cost-effectiveness of drugs from 4 classes of antihypertensive medications commonly used in Nigeria in management of hypertension without compelling indication to use a particular antihypertensive drug. METHODS: The study employed decision analytic modeling. Interventions were obtained from a meta-analysis. The Markov process model calculated clinical outcomes and costs during a life cycle of 30 years of 1000 hypertensive patients stratified by 3 cardiovascular risk groups, under the alternative intervention scenarios. Quality adjusted life year (QALY) was used to quantify clinical outcome. The average cost of treatment for the 1000 patient was tracked over the Markov cycle model of the alternative interventions and results were presented in 2010 US Dollars. Probabilistic cost-effectiveness analysis was performed using Monte Carlo simulation, and results presented as cost-effectiveness acceptability frontiers. Expected value of perfect information (EVPI) and expected value of parameter perfect information (EVPPI) analyses were also conducted for the hypothetical population. RESULTS: Thiazide diuretic was the most cost-effective option across the 3 cardiovascular risk groups. Calcium channel blocker was the second best for Moderate risk and high risk with a willingness to pay of at least 2000$/QALY. The result was robust since it was insensitive to the parameters alteration. CONCLUSIONS: The result of this study showed that thiazide diuretic followed by calcium channel blocker could be a feasible strategy in order to ensure that patients in Nigeria with hypertension are better controlled.