The goal of a non-inferiority randomized trial is to demonstrate that an experimental treatment is not unacceptably worse than a standard treatment. The experimental treatment is known to have less toxicity or other quality-of-life benefits when compared with the standard treatment, so that a small decrement in efficacy would be acceptable. Interim monitoring of randomized trials is used to stop trials early if the conclusions of the trial become definitive early. In the context of a non-inferiority trial, of special interest is stopping a trial early when the experimental treatment is inferior to the standard treatment. Methods for performing interim monitoring of non-inferiority trials are reviewed for their ability to minimize patient exposure to inferior experimental treatments. Examples of trials from the literature are discussed along with a computer simulation of a simple non-inferiority monitoring rule. Interim monitoring for non-inferiority trials is shown to substantially reduce the exposure of patients to inferior therapies when, in fact, the experimental treatment is inferior to the standard treatment. Interim monitoring rules typically used in superiority trials may be sub-optimal for non-inferiority trials, and may unnecessarily expose patients to inferior therapies. Examples of trials with inferior experimental arms and trials with sub-optimal monitoring rules are given. Appropriate interim monitoring of non-inferiority trials can reduce the exposure of patients to inferior therapies when the experimental treatment is inferior to the standard treatment.

中文翻译：

---

非劣效性试验的中期监测：最大程度地减少患者接受劣等疗法的机会。

非劣效性随机试验的目的是证明实验治疗不会比标准治疗差很多。已知与标准治疗相比，实验治疗具有较小的毒性或其他生活质量益处，因此功效的小幅下降将是可以接受的。如果试验的结论早日确定，则使用随机试验的中期监测来尽早终止试验。在非劣效性试验的背景下，特别感兴趣的是，当实验性治疗劣于标准治疗时，应尽早停止试验。审查了对非劣效性试验进行中期监测的方法，以了解其将患者对劣质实验性治疗的影响降至最低的能力。讨论了来自文献的试验示例以及简单的非自卑性监测规则的计算机模拟。当非劣效性临床试验的中期疗效低于标准疗法时，对非劣效性试验的中期监测表明，该疗法可显着减少患者接受劣等疗法的风险。优越性试验中通常使用的临时监测规则对于非劣效性试验可能不是最佳选择，并且可能会使患者不必要地接受劣等疗法。给出了使用劣等实验装置进行试验和采用次优监测规则进行试验的示例。当实验性治疗不如标准治疗时，对非劣效性试验进行适当的中期监测可以减少患者接受劣质性治疗的机会。