Sampaio C, Ferreira J, Costa J
Instituto de Farmacologia e Terapêutica Geral, Faculdade de Medicina de Lisboa.
Rev Port Cardiol. 2000 Dec;19(12):1303-8.
This is a narrative review of a concept--number needed to treat (NNT). The proprieties of NNTs are described. Furthermore NNTs as important tools for medical decision are discussed. In particular, conditions that make calculus and the interpretation of NNTs somewhat more complex are commented. Namely, we consider situations where the results are not primarily binary or are expressed as "time to event" or come from a meta-analysis. The inconsistencies that might occur when NNTs are calculated from meta-analysis are discussed in some detail. Definitions for parameters derived from NNTs, as numbers needed to harm (NNH), unqualified success (NNTUS) and unmitigated failure (NNHUF) are given. Finally the usefulness of NNTs and absolute risk reductions to communicate risk to individual patients are considered. It is concluded that despite NNTs being powerful tools for medical decision, in the case of communicating risks to the individual patient absolute risks might be preferable.
这是一篇关于“治疗所需人数（NNT）”这一概念的叙述性综述。文中描述了NNT的特性。此外，还讨论了NNT作为医疗决策重要工具的情况。特别评论了使NNT的计算和解释变得更为复杂的一些情况。具体而言，我们考虑了结果并非主要为二元性、以“事件发生时间”表示或来自荟萃分析的情形。文中较为详细地讨论了从荟萃分析计算NNT时可能出现的不一致性。给出了从NNT衍生出的参数定义，如伤害所需人数（NNH）、无附加条件成功所需人数（NNTUS）和完全失败所需人数（NNHUF）。最后，探讨了NNT和绝对风险降低率在向个体患者传达风险方面的作用。得出的结论是，尽管NNT是医疗决策的有力工具，但在向个体患者传达风险时，绝对风险可能更可取。
