Cost per millimeter of mercury lowering is a measure of economic value for antihypertensive agents.

The use of pharmacoeconomic analyses to evaluate the appropriateness of treatment regimens is increasing rapidly. Trials that study the efficacy of antihypertensive agents do not often measure long-term cardiovascular morbidity and mortality, so complementary methods are needed to evaluate the cost-effectiveness of these agents. One method is to compare agents on the basis of their costs and blood pressure-lowering efficacy, producing a ratio of cost per millimeter of mercury lowering, or cost/mm Hg. This provides a simple, transparent method with which to evaluate the cost-effectiveness of antihypertensive agents. It also allows the cost-effectiveness of a blood pressure treatment to be assessed in terms of ambulatory blood pressure data. The use of cost/mm Hg requires assumptions that tolerability of agents is comparable and that blood pressure lowering is a valid surrogate for cardiovascular risk reduction. Given the emergence of new treatments that have differences in blood pressure efficacy, cost/mm Hg is likely to become increasingly used as an indicator of economic value.