Use of pharmacoeconomics in prescribing research. Part 2: cost-minimization analysis--when are two therapies equal?

UNLABELLED: This is the second paper in a series looking at pharmacoeconomic methods. The first paper discussed how costs are identified for pharmacoeconomic studies. This article will examine one of the four main evaluation methods in health economics, cost-minimization analysis (CMA). The remaining three methods (cost-effectiveness, cost-utility and cost-benefit analysis) will be discussed in later papers. KEY MESSAGES: Cost-minimization is the appropriate form of economic analysis to carry out whenever two drugs have the same clinical effect. True equivalence studies are uncommon; a more useful approach is to assess the size of the confidence interval around the difference between treatments and determine whether it excludes clinically relevant effects. The critical issue for cost-minimization analyses is determining equi-effective doses.