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arXiv 1809.07068stat.ME
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随机试验中连续终点的测量误差:问题与对策

Measurement error in continuous endpoints in randomised trials: problems and solutions

Linda Nab, Rolf H. H. Groenwold, Paco M. J. Welsing, Maarten van Smeden

摘要:

在随机试验中,连续终点的测量通常存在一定程度的误差。本研究探讨了忽略测量误差的影响,并提出了在存在测量误差的情况下改进统计推断的方法。连续端点的三种主要类型的测量误差被认为是:经典的,系统的和微分。对于每一种测量误差类型,提出了一种校正效果估计器。对修正后的估计量和几种置信区间估计方法进行了模拟试验。这些方法结合了关于未纳入试验的个体(外部校准样本)终点的易出错和无错误测量的信息。我们表明,如果连续终点的测量误差被忽略,处理效应估计是无偏的,当测量误差是经典的,而第二类错误增加在一个给定的样本量。相反,当测量误差是系统误差或微分误差时,估计器可能基本上有偏。在这些情况下,使用来自外部校准样本的信息可以在很大程度上防止偏倚,并改善推断,其中所需的样本量随着易出错和无错误端点之间的关联强度的降低而增加。测量误差校正已经使用一个小的(外部)校准样本,以改善推论,并应考虑在试验中的错误倾向的终点。建议的校正方法的实施是由一个新的软件包为R。

英文摘要:

In randomised trials, continuous endpoints are often measured with some degree of error. This study explores the impact of ignoring measurement error, and proposes methods to improve statistical inference in the presence of measurement error. Three main types of measurement error in continuous endpoints are considered: classical, systematic and differential. For each measurement error type, a corrected effect estimator is proposed. The corrected estimators and several methods for confidence interval estimation are tested in a simulation study. These methods combine information about error-prone and error-free measurements of the endpoint in individuals not included in the trial (external calibration sample). We show that if measurement error in continuous endpoints is ignored, the treatment effect estimator is unbiased when measurement error is classical, while Type-II error is increased at a given sample size. Conversely, the estimator can be substantially biased when measurement error is systematic or differential. In those cases, bias can largely be prevented and inferences improved upon using information from an external calibration sample, of which the required sample size increases as the strength of the association between the error-prone and error-free endpoint decreases. Measurement error correction using already a small (external) calibration sample is shown to improve inferences and should be considered in trials with error-prone endpoints. Implementation of the proposed correction methods is accommodated by a new software package for R.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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