THE B-VALUE - A TOOL FOR MONITORING DATA
THE B-VALUE - A TOOL FOR MONITORING DATA
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DOI：
10.2307/2531870
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发表时间：
1988-06-01
期刊：
影响因子：
1.9
通讯作者：
WITTES, J
中科院分区：
文献类型：
--
作者：
LAN, KKG;WITTES, J
本文考虑了监测非顺序设计的实验中缓慢积累的数据的问题。我们描述了使用 B 值（它是变换后的 Z 值）来计算条件功效。在数据监测中，临时 Z 值不允许对研究结束进行简单预测。此外，由于 Z 值与 P 值的普遍关联，因此经常被误解。如果将观察到的趋势视为布朗运动过程的实现，则 B 值及其分解允许在各种假设下对研究结束进行简单的外推。应用程序包括一样本和二样本 Z 检验、二样本 Wilcoxon 秩和检验以及对数秩检验。
This paper considers the problem of monitoring slowly accruing data from a nonsequentially designed experiment. We describe the use of the B-value, which is a transformed Z-value, for the calculation of conditional power. In data monitoring, interim Z-values do not allow simple projections to the end of the study. Moreover, because of their popular association with P-values, Z-values are often misinterpreted. If observed trends are viewed as the realization of a Brownian motion process, the B-value and its decomposition allow simple extrapolations to the end of the study under a variety of hypotheses. Applications are presented to one- and two-sample Z-tests, the two-sample Wilcoxon rank sum test, and the log-rank test.