A menu-driven facility for sample-size calculations in cluster randomized controlled trials
A menu-driven facility for sample-size calculations in cluster randomized controlled trials
复制标题
DOI：
10.1177/1536867x1301300109
复制
发表时间：
2013-01-01
期刊：
影响因子：
4.8
通讯作者：
Marsh, Jen
中科院分区：
文献类型：
--
作者：
Hemming, Karla;Marsh, Jen
我们介绍了Stata菜单驱动的命令clustersampsi，它计算样本量，可检测的差异，并为集群随机对照试验的权力。该命令允许连续、二元和比率结果（正态近似），用于两个相等大小的组中双侧检验的比较。该命令允许指定可用群集的数量、群集大小或平均群集大小沿着群集大小变化的估计值。当可用的聚类数不足以检测预定功效下所需的差异时，clustersampi将返回预定设计沿着所需的最小聚类数以及最小可检测差异和最大可实现功效（均为预定聚类数）。聚类异质性可以通过聚类内相关性或变异系数来参数化。该命令通过示例进行说明。
We introduce the Stata menu-driven command clustersampsi, which calculates sample sizes, detectable differences, and power for cluster randomized controlled trials. The command permits continuous, binary, and rate outcomes (with normal approximations) for comparisons of two-sided tests in two equal-sized arms. The command allows for specification of the number of clusters available, or the cluster size, or the average cluster size along with an estimate of the variation of cluster sizes. When the number of clusters available is insufficient to detect the required difference at the prespecified power, clustersampsi will return the minimum number of clusters required under the prespecified design along with the minimum detectable difference and maximum achievable power (both for the prespecified number of clusters). Cluster heterogeneity can be parameterized by using either the intracluster correlation or the coefficient of variation. The command is illustrated via examples.