van Harten P N
Symfora Groep, Amersfoort, The Netherlands.
Tijdschr Psychiatr. 2008;50(6):337-43.
The concepts developed in evidence-based medicine, together with clinical experience, are the major principles on which clinical decisions are made. One of the concepts is number needed to treat (NNT), which means the number of patients who have to be treated either to prevent one additional unfavourable outcome or to achieve one additional favourable outcome. The NNT is dependent on the baseline risk (the risk of occurrence at baseline): the higher the baseline risk, the lower will be the NNT (which is more favourable). In contrast, the relative risk reduction is fairly independent of the baseline risk. NNT and number needed to harm provide numerical arguments for deciding whether a particular treatment does more good than harm.
循证医学中提出的概念，连同临床经验，是做出临床决策的主要原则。其中一个概念是需治疗人数（NNT），即必须接受治疗以预防一个额外不良结局或实现一个额外良好结局的患者数量。NNT取决于基线风险（基线时发生的风险）：基线风险越高，NNT越低（这更有利）。相比之下，相对风险降低率相当独立于基线风险。NNT和伤害需治人数为决定某种特定治疗的利弊提供了数值依据。
