On determination of sample size in hierarchical binomial models.
On determination of sample size in hierarchical binomial models.
复制标题
关于分层二项式模型中样本量的确定。
DOI：
10.1002/sim.855
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发表时间：
2001
影响因子：
2
通讯作者：
Normand,SL
中科院分区：
文献类型：
--
作者：
Zou,KH;Normand,SL
我们考虑了一个两阶段和一个三阶段的分层设计，其中包含每个集群中没有单元的k集群的影响。在两阶段模型中，假定离散响应的条件分布为均值为nθi（I=1，…，k）的独立二项分布。假设成功概率θi在集群之间是可交换的，每个集群都产生于beta分布。在三阶段模型中，假设beta分布中的参数具有独立的gamma分布。每个簇的大小n是由θi的函数决定的。利用马尔可夫链蒙特卡罗和蒙特卡罗模拟计算θi的各种函数的中央后验间隔的长度。描述了几种先验分布，并给出了表格。本文对两阶段和三阶段模型下的样本量计算方法进行了说明和比较，以设计一项多机构研究，以评估充血性心力衰竭患者队列的出院计划率的适宜性。版权所有©2001约翰威利父子有限公司
We consider a two‐ and a three‐stage hierarchical design containing the effects ofkclusters withnunits per cluster. In the two‐stage model, the conditional distribution of the discrete responseYiis assumed to be independent binomial with mean nθi(I=1,…,k). The success probabilities,θi's, are assumed exchangeable across thekclusters, each arising from a beta distribution. In the three‐stage model, the parameters in the beta distribution are assumed to have independent gamma distributions. The size of each cluster,n, is determined for functions ofθi. Lengths of central posterior intervals are computed for various functions of theθi's using Markov chain Monte Carlo and Monte Carlo simulations. Several prior distributions are characterized and tables are provided fornwith givenk. Methods for sample size calculations under the two‐ and three‐stage models are illustrated and compared for the design of a multi‐institutional study to evaluate the appropriateness of discharge planning rates for a cohort of patients with congestive heart failure. Copyright © 2001 John Wiley & Sons, Ltd.