Liu Xiaofeng Steven
Department of Educational Studies, University of South Carolina, Columbia, SC, USA
Eval Health Prof. 2014 Dec;37(4):470-87. doi: 10.1177/0163278713498392. Epub 2013 Aug 1.
This article shows how to compute statistical power for testing the main effect of treatment in three-arm cluster randomized trials. Using orthogonal coding, we derive the exact test statistic of the treatment effect and its non-central distribution. The non-centrality parameter in the omnibus test is found to be related to the non-centrality parameters in the contrast tests. A study of physician and pharmacist comanagement of patients' blood pressure is used as an example to show the power computation in a three-arm cluster randomized trial.
本文展示了如何计算三臂整群随机试验中治疗主效应检验的统计功效。利用正交编码，我们推导出了治疗效应的精确检验统计量及其非中心分布。发现综合检验中的非中心参数与对比检验中的非中心参数相关。以一项关于医生和药剂师共同管理患者血压的研究为例，展示了三臂整群随机试验中的功效计算。
