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arXiv 2602.03218stat.MEstat.AP
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blinded样本量重新估计考虑中期试验估计中的不确定性

Blinded sample size re-estimation accounting for uncertainty in mid-trial estimation

The University of Osaka(大阪大学);National Cerebral and Cardiovascular Center(国立循环器病研究中心);University Medical Center Göttingen(哥廷根大学医学中心)

Hirotada Maeda, Satoshi Hattori, Tim Friede

AI总结:

本文提出了一种考虑盲审查中估计误差的样本量重新估计方法,以提高随机对照试验的统计效力。

摘要:

为了使随机对照试验得出结论,设计阶段准确设定目标样本量非常重要。比较两个正态总体时,样本量计算需要指定方差,除了治疗效应外,规格不正确会导致研究欠力。盲样本人样本量重新估计是一种最小化得出不明确研究风险的方法。现有方法提出使用可从盲数据中估计的总(单样本)方差,而无需知道治疗分配。我们证明,由于该估计量的期望值大于或等于真实方差,单样本方差方法可以被视为在盲审查中提供方差的上限。这种最坏情况的评估可能有助于减少欠力研究的风险。然而,盲审查小样本量仍可能导致欠力研究。我们提出了一种改进的方法,利用盲审查中的方差估计误差,使用方差的上置信限。类似的想法已在外部试点研究的设置中被提出。此外,我们开发了一种方法来选择适当的置信水平,使得重新估计的样本量达到目标功率。数值研究显示,我们的方法表现良好,并优于现有方法。所提出的过程由最近的随机临床试验所激励和说明。

英文摘要:

For randomized controlled trials to be conclusive, it is important to set the target sample size accurately at the design stage. Comparing two normal populations, the sample size calculation requires specification of the variance other than the treatment effect and misspecification can lead to underpowered studies. Blinded sample size re-estimation is an approach to minimize the risk of inconclusive studies. Existing methods proposed to use the total (one-sample) variance that is estimable from blinded data without knowledge of the treatment allocation. We demonstrate that, since the expectation of this estimator is greater than or equal to the true variance, the one-sample variance approach can be regarded as providing an upper bound of the variance in blind reviews. This worst-case evaluation can likely reduce a risk of underpowered studies. However, blinded reviews of small sample size may still lead to underpowered studies. We propose a refined method accounting for estimation error in blind reviews using an upper confidence limit of the variance. A similar idea had been proposed in the setting of external pilot studies. Furthermore, we developed a method to select an appropriate confidence level so that the re-estimated sample size attains the target power. Numerical studies showed that our method works well and outperforms existing methods. The proposed procedure is motivated and illustrated by recent randomized clinical trials.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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