Methods to reduce the impact of intraclass correlation in group-randomized trials
Methods to reduce the impact of intraclass correlation in group-randomized trials
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DOI：
10.1177/0193841x02239019
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发表时间：
2003-02-01
影响因子：
0.9
通讯作者：
Blitstein, JL
中科院分区：
文献类型：
--
作者：
Murray, DM;Blitstein, JL
本研究报告了组间随机试验(GRTS)中使用的因变量的组内相关性(ICC)。作者还证明了两种建议的方法，以减少国际商会在GRTS的影响，这两种方法是建模时间和回归调整协变量。他们编码和分析了来自代表21项研究的17篇已发表、已出版和未发表的文章的1188个ICC估计值。研究结果证实，这两种方法都可以提高被证明在GRTS中常见情况下有效的分析效率。计划GRTS的研究人员应该获得与他们计划的分析相匹配的ICC估计，以便他们能够适当地调整他们的研究规模。
This study reports intraclass correlation (ICC)for dependent variables used in group-randomized trials (GRTs). The authors also document the effect of two methods suggested to reduce the impact of ICC in GRTs; these two methods are modeling time and regression adjustment for covariates. They coded and analyzed 1,188 ICC estimates from 17 published, in press, and unpublished articles representing 21 studies. Findings confirm that both methods can improve the efficiency of analyses shown to be valid across conditions common in GRTs. Investigators planning GRTs should obtain ICC estimates matched to their planned analysis so that they can size their studies properly.