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arXiv 2201.12921stat.ME
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协变量调整与组序贯、信息自适应设计相结合提高随机试验效率

Combining Covariate Adjustment with Group Sequential, Information Adaptive Designs to Improve Randomized Trial Efficiency

Kelly Van Lancker, Joshua Betz, Michael Rosenblum

摘要:

在临床试验中,通过适当调整统计分析中的基线变量,有可能提高精密度并减少所需的样本量。这称为协变量调整。尽管监管机构建议进行协变量调整,但它仍然未得到充分利用,导致试验效率低下。我们解决了两个障碍,使其具有挑战性的协变量调整。第一个障碍是在成组序贯设计(GSDs)中,许多协变量调整估计量与常用的边界不相容。第二个障碍是设计阶段的不确定性,即协变量调整会带来多少精度增益。我们提出了一种方法,修改原来的估计,使其成为兼容GSD,同时增加或保持不变的估计的精度。我们的方法允许使用任何渐近线性估计,其中包括许多随机试验中使用的估计。在此基础上,我们建议使用信息自适应设计,即继续试验,直到达到所需的信息水平。这样的设计适应于精度增益的量,并且可以导致更快、更有效的试验,而不牺牲有效性或功率。我们评估估计性能模拟功能的一个完整的中风试验。

英文摘要:

In clinical trials, there is potential to improve precision and reduce the required sample size by appropriately adjusting for baseline variables in the statistical analysis. This is called covariate adjustment. Despite recommendations by regulatory agencies in favor of covariate adjustment, it remains underutilized leading to inefficient trials. We address two obstacles that make it challenging to use covariate adjustment. A first obstacle is the incompatibility of many covariate adjusted estimators with commonly used boundaries in group sequential designs (GSDs). A second obstacle is the uncertainty at the design stage about how much precision gain will result from covariate adjustment. We propose a method that modifies the original estimator so that it becomes compatible with GSDs, while increasing or leaving unchanged the estimator's precision. Our approach allows the use of any asymptotically linear estimator, which covers many estimators used in randomized trials. Building on this, we propose using an information adaptive design, that is, continuing the trial until the required information level is achieved. Such a design adapts to the amount of precision gain and can lead to faster, more efficient trials, without sacrificing validity or power. We evaluate estimator performance in simulations that mimic features of a completed stroke trial.

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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