Evaluation of sample size and power for multi-arm survival trials allowing for non-uniform accrual, non-proportional hazards, loss to follow-up and cross-over
Evaluation of sample size and power for multi-arm survival trials allowing for non-uniform accrual, non-proportional hazards, loss to follow-up and cross-over
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DOI：
10.1002/sim.2517
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发表时间：
2006-08-15
影响因子：
2
通讯作者：
Parmar, M. K. B.
中科院分区：
文献类型：
--
作者：
Barthel, F. M. -S.;Babiker, A.;Parmar, M. K. B.
我们提出了一个基于比较两种或多种生存分布的生存研究样本大小计算的一般框架，使用包括logrank检验在内的一类检验中的任何一种。在这一框架内纳入了可能存在的不均匀、交错患者进入、非比例危险、随访损失和治疗变化（包括治疗组之间的交叉）。该框架在本质上是非常通用的，并且基于使用分段指数分布对生存分布进行建模。我们举例说明了该方法的使用，并通过仿真研究探讨了其有效性。这些研究表明，不调整随访损失、非比例风险或交叉可能导致功率的显著改变，或同等地，对样本量产生显著影响。该方法已在免费提供的ART程序（用于Stata）中实施。我们的调查表明，ART是第一个允许合并所有这些元素的软件。还考虑了对方法的进一步扩展，例如logrank检验的非本地替代方法。版权所有(c) 2006约翰威利父子有限公司
1We present a general framework for sample size calculation in survival studies based on comparing two or more survival distributions using any one of a class of tests including the logrank test. Incorporated within this framework are the possible presence of non-uniforin staggered patient entry, non-proportional hazards, loss to follow-up and treatment changes including cross-over between treatment arms. The framework is very general in nature and is based on using piecewise exponential distributions to model the survival distributions. We illustrate the use of the approach and explore its validity using simulation studies. These studies have shown that not adjusting for loss to follow-up, non-proportional hazards or cross-over can lead to significant alterations in power or equivalently, a marked effect on sample size. The approach has been implemented in the freely available program ART (for Stata). Our investigations suggest that ART is the first software to allow incorporation of all these elements. Further extensions to the methodology such as non-local alternatives for the logrank test are also considered. Copyright (c) 2006 John Wiley & Sons, Ltd.