Lan K K, Friedman L
Control Clin Trials. 1986 Mar;7(1):1-7. doi: 10.1016/0197-2456(86)90002-4.
The typical long-term trial has a data monitoring committee. A primary responsibility of this committee is maintenance of patient safety. In this role, this committee is likely to recommend stopping a trial when a new treatment appears worse than the control even when the difference is not statistically significant or if it appears that the new treatment will not be clearly beneficial. Several approaches, including the use of conditional power, can be used to help the monitoring committee decide if a study should be stopped early because of a harmful or insufficiently effective treatment. These monitoring approaches have altered the way in which we view one-sided or two-sided tests of significance.
典型的长期试验设有数据监测委员会。该委员会的主要职责之一是维护患者安全。在此职责下，即使差异无统计学意义，但若新疗法看起来比对照疗法差，或者新疗法似乎不会带来明显益处，该委员会很可能会建议停止试验。包括使用条件检验效能在内的几种方法，可用于帮助监测委员会决定一项研究是否应因治疗有害或疗效不足而提前终止。这些监测方法改变了我们看待单侧或双侧显著性检验的方式。
