INTERNAL PILOT-STUDIES FOR ESTIMATING SAMPLE-SIZE
INTERNAL PILOT-STUDIES FOR ESTIMATING SAMPLE-SIZE
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DOI：
10.1002/sim.4780132309
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发表时间：
1994-12-30
影响因子：
2
通讯作者：
DAY, SJ
中科院分区：
文献类型：
--
作者：
BIRKETT, MA;DAY, SJ
我们发展了这样一种想法，即使用最初进入临床试验的“少数”患者的数据来估计最终试验规模，如果存在真正的差异，则需要具有拒绝H-0而支持H-1的指定功率。当比较来自正态分布数据的均值时，如果使用至少约20个自由度来估计残差方差，则对检验规模、功率或预期试验规模没有重要影响。提出了使用较大的内部试点研究的相对优点和缺点。这些问题围绕着对最终研究规模、招募率、随访持续时间的粗略预期，以及防止将非盲随机化代码传播给调查人员和参与编辑和检查数据的人员的能力的实际限制。
We develop the idea of using data from the first 'few' patients entered in a clinical trial to estimate the final trial size needed to have specified power for rejecting H-0 in favour of H-1 if a real difference exists. When comparing means derived from Normally distributed data, there is no important effect on test size, power or expected trial size, provided that a minimum of about 20 degrees of freedom are used to estimate residual variance. Relative advantages and disadvantages of using larger internal pilot studies are presented. These revolve around crude expectations of the final study size, recruitment rate, duration of follow-up and practical constraints on the ability to prevent the circulation of unblinded randomization codes to investigators and those involved in editing and checking data.