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首页> 外文期刊>The Canadian Journal of Neurological Sciences: le Journal Canadien des Sciences Neurologiques >Alternatives to placebo-controlled trials.
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Alternatives to placebo-controlled trials.

机译：安慰剂对照试验的替代方法。

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Until recently, the gold standard for assessing the efficacy and effectiveness of new medications has been the placebo-control randomized clinical trial (RCT). However, there are serious ethical concerns about placing patients on a placebo when effective treatments exist. Further, if a new agent is tested only against a placebo, there is no guarantee that it is more effective, or even as effective, as an existing agent. For these and other reasons, ethicists and regulatory bodies have said that, under these circumstances, new drugs should be tested against an active agent. There are three types of such trials: superiority, equivalence, and non-inferiority. In superiority trials, the goal is to establish that the new drug is better (i.e., more effective, or with a more benign side-effect profile) than the standard. Because such trials require much larger sample sizes than placebo-control studies, and are rarely required to bring a drug onto market, they are rarely done. In equivalence trials, the aim isto show that the new and standard agents have similar degrees of effectiveness or adverse events. Due to sample size requirements, most studies of new drugs are non-inferiority trials, in which it is sufficient to demonstrate that the new drug is not significantly worse than the existing ones. However, there are methodological concerns with equivalence and non-inferiority trials, including (a) an inability to determine if the drugs were equally good or equally bad; (b) poorly executed trials with low power can be mistaken for "proving" equivalence or non-inferiority; (c) the equivalence interval is arbitrary; (d) successive non-inferiority trials may lead to a gradual reduction in effectiveness; and (e) often larger trials are necessary. The paper also discusses "add on trials." It is recommended that, even when existing drugs exist, trials should consist of at least three arms, one of which is a placebo. This paper briefly considers the ethics of placebo, and conditions are stated under which such studies can be conducted.
机译：直到最近，评估新药功效的金标准一直是安慰剂对照随机临床试验（RCT）。但是，在存在有效治疗方法的情况下，将患者置于安慰剂上存在严重的伦理问题。此外，如果仅针对安慰剂对新药进行测试，则不能保证它比现有药更有效，甚至同样有效。由于这些及其他原因，伦理学家和监管机构表示，在这种情况下，应针对活性药物对新药进行测试。这种试验分为三种类型：优越性，等效性和非劣等性。在优越性试验中，目标是确定新药比标准药更好（即更有效，或具有更好的副作用）。由于此类试验需要比安慰剂对照研究大得多的样本量，并且几乎不需要将药物投放市场，因此很少进行。在等效试验中，目的是证明新药和标准药具有相似程度的有效性或不良事件。由于样本量的要求，大多数新药的研究都是非劣效性试验，足以证明该新药并不比现有药物差很多。但是，在等效性和非劣效性试验中仍存在方法论上的问题，其中包括：（a）无法确定药物的优劣程度; （b）权力低下的执行不力的审判可被误认为是“证明”同等或非自卑的; （c）等效间隔是任意的; （d）连续的非劣效性试验可能会导致有效性逐渐降低; （e）通常需要进行更大的试验。该论文还讨论了“附加试验”。建议即使存在现有药物，试验也应至少包括三个部分，其中之一是安慰剂。本文简要考虑了安慰剂的伦理学，并阐明了可进行此类研究的条件。

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