Office for Health Economics (OHE) , London , UK.
London School of Economics , London , UK.
Front Public Health. 2016 Jul 7;4:107. doi: 10.3389/fpubh.2016.00107. eCollection 2016.
The precautionary principle (PP) has been used in the evaluation of the effectiveness and/or cost-effectiveness of interventions designed to prevent future harms in a range of activities, particularly in the area of the environment. Here, we provide details of circumstances under which the PP can be applied to the topic of harm reduction in Public Health. The definition of PP that we use says that the PP reverses the onus of proof of effectiveness between an intervention and its comparator when the intervention has been designed to reduce harm. We first describe the two frameworks used for health-care evaluation: evidence-based medicine (EBM) and decision theory (DT). EBM is usually used in treatment effectiveness evaluation, while either EBM or DT may be used in evaluating the effectiveness of the prevention of illness. For cost-effectiveness, DT is always used. The expectation in Public Health is that interventions employed to reduce harm will not actually increase harm, where "harm" in this context does not include opportunity cost. That implies that an intervention's effectiveness can often be assumed. Attention should therefore focus on its cost-effectiveness. This view is consistent with the conclusions of DT. It is also very close to the PP notion of reversing the onus of proof, but is not consistent with EBM as normally practiced, where the onus is on showing a new practice to be superior to usual practice with a sufficiently high degree of certainty. Under our definitions, we show that where DT and the PP differ in their evaluation is in cost-effectiveness, but only for decisions that involve potential catastrophic circumstances, where the nation-state will act as if it is risk-averse. In those cases, it is likely that the state will pay more, and possibly much more, than DT would allow, in an attempt to mitigate impending disaster. That is, the rules that until now have governed all cost-effectiveness analyses are shown not to apply to catastrophic situations, where the PP applies.
预防原则（PP）已被用于评估旨在预防未来危害的干预措施的有效性和/或成本效益，这些干预措施涉及广泛的活动，特别是在环境领域。在这里，我们提供了可以将 PP 应用于公共卫生减少伤害主题的情况下的详细信息。我们使用的 PP 定义是，当干预措施旨在减少伤害时，PP 将干预措施与其比较的有效性证明责任颠倒。我们首先描述了用于医疗保健评估的两个框架：循证医学（EBM）和决策理论（DT）。EBM 通常用于治疗效果评估，而 EBM 或 DT 都可用于评估预防疾病的有效性。对于成本效益，始终使用 DT。公共卫生的期望是，用于减少伤害的干预措施实际上不会增加伤害，在这种情况下，“伤害”不包括机会成本。这意味着干预措施的有效性通常可以假定。因此，应将注意力集中在其成本效益上。这种观点与 DT 的结论一致。它也非常接近 PP 的反转举证责任的概念，但与通常实践中的 EBM 不一致，在 EBM 中，举证责任在于证明新实践比通常实践具有足够高的确定性具有优越性。根据我们的定义，我们表明，DT 和 PP 在其评估中的区别在于成本效益，而只是在涉及潜在灾难性情况的决策中，国家将表现出对风险的规避态度。在这些情况下，国家可能会支付更多的费用，甚至可能会支付远远超过 DT 允许的费用，以试图减轻即将到来的灾难。也就是说，直到现在一直支配所有成本效益分析的规则不适用于 PP 适用的灾难性情况。
