Cost Utility of Rapid Polymerase Chain Reaction-Based Influenza Testing: What Should a Clinician Make of This Analysis?

Abstract

Although few clinicians relish reading an economic analysis, it is an increasingly important part of the evidence base. The argument that financial considerations should not influence treatment decisions is difficult to sustain in the light of increasing health care costs and the dire economic situation, but clinicians are rightly wary of letting population-level economic analyses drive decisionmaking for individual patients. The complexity of economic analysis and use of unfamiliar terminology does not help, but it is important that clinicians read and understand economic analyses, such as the one undertaken by Dugas et al, because, contrary to the accusation that economic analysis allows clinical decisionmaking to be dictated by cost, it is usually effectiveness that determines costeffectiveness. This is apparent in the analysis undertaken by Dugas et al. The rapid diagnostic test was estimated to have sensitivity of 91% and specificity of 99%, yet the “treat-all” strategy was cost-effective in the base case analysis, with an incremental cost-effectiveness ratio of $6,246 per qualityadjusted life-year gained, compared with treating only patients with a positive rapid diagnostic test result. In other words, the benefit of treating the additional 9% of patients with falsenegative results in the treat-all strategy was worth the cost of not only treating patients with false-negative test results but also treating the large number of patients with true negative test results, who incur additional costs without accruing benefit. It is worth considering how cost-effectiveness has been estimated in this analysis and what the incremental costeffectiveness ratio of $6,246 per quality-adjusted life-year gained actually means. Cost-effectiveness analysis involves measuring costs and outcomes. In some analyses, the cheapest strategy is the most effective and it thus “dominates” the alternatives. Interpretation of the results is easy, although it is worth asking whether complex analysis is required to generate such an obvious answer. More often economic analysis shows that the most effective strategy is more expensive, so we need to work out whether the additional benefits justify the additional costs. The base case comparison between treating all and basing treatment on the rapid diagnostic test provides a good example. i