Cluster size variability and imbalance in cluster randomized controlled trials
Cluster size variability and imbalance in cluster randomized controlled trials
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DOI：
10.1002/sim.4050
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发表时间：
2010-12-20
影响因子：
2
通讯作者：
Carter, Ben
中科院分区：
文献类型：
--
作者：
Carter, Ben
随机对照试验越来越多地用于评估医疗干预措施。研究发现，集群大小的可变性导致整体有效样本量的减少。虽然集群试验的报告标准已经开始演变，但需要更大程度的透明度，以确保提供有力的证据。应避免使用招募的患者数量来总结招募率，以支持说明累积把握度并解释聚类变异性的改进指标。来自四个试验的数据显示集群大小的变化和不平衡之间的联系。此外，使用模拟，它表明，通过随机化使用两个块的随机化策略和加权第二集群大小的招聘，机会不平衡可以最小化。版权所有（C）2010约翰威利父子有限公司
Cluster randomized controlled trials are increasingly used to evaluate medical interventions. Research has found that cluster size variability leads to a reduction in the overall effective sample size. Although reporting standards of cluster trials have started to evolve, a far greater degree of transparency is needed to ensure that robust evidence is presented. The use of the numbers of patients recruited to summarize recruitment rate should be avoided in favour of an improved metric that illustrates cumulative power and accounts for cluster variability. Data from four trials is included to show the link between cluster size variability and imbalance. Furthermore, using simulations it is demonstrated that by randomising using a two block randomization strategy and weighting the second by cluster size recruitment, chance imbalance can be minimized. Copyright (C) 2010 John Wiley & Sons, Ltd.