The role of measurement reliability in clinical trials.
The role of measurement reliability in clinical trials.
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DOI：
10.1191/1740774504cn057oa
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发表时间：
2004-01-01
期刊：
影响因子：
--
通讯作者：
Lachin, John M
中科院分区：
文献类型：
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作者：
Lachin, John M
临床试验中的结果测量的主要特征之一，以及一般的任何测量，都是其可靠性。可靠性是指在同一受试者或样本中随机重复测量时的重现性。可靠性经常与有效性混淆，有效性指的是变量正确测量感兴趣的潜在特征的程度。可靠性系数是所有变异的比例的估计值，该变异不是由于测量误差引起的，并且很容易从重复测量中估计。测量的可靠性决定了回归模型中的最大相关性或R2和斜率（或效应大小），用于分类或预测时的灵敏度和特异性，以及采用测量的统计检验的功效。所有这些都随着测量的可靠性下降而下降。在选择临床试验的主要结局指标以及选择用于评估合格性和排除的指标时，测量的可靠性是一个重要的考虑因素。测量的可靠性应通过基于随机选择的重复评估的质量控制程序进行评估和保证。正如一项研究的功效在最终出版物中报告一样，结果和合格性测量的可靠性也应该报告，以便作者更好地描述，读者更好地理解，研究结果不精确的来源，以及那些遵循以改进未来试验设计的人。
One of the principal characteristics of an outcome measure in a clinical trial, and any measurement in general, is its reliability. Reliability refers to the reproducibility of the measurement when repeated at random in the same subject or specimen. Reliability is often confused with validity, which refers to the extent to which the variable properly measures the underlying trait of interest. The coefficient of reliability is an estimate of the proportion of all variation that is not due to measurement error and is readily estimated from replicate measurements. The reliability of a measurement determines its maximal correlation or R2 and slope (or effect size) in regression models, its sensitivity and specificity when used for classifications or predictions, and the power of a statistical test employing the measurement. All decline as the reliability of the measure declines. The reliability of a measurement is an important consideration in the choice of the primary outcome measure for a clinical trial and in the choice of measures used for assessment of eligibility and exclusion. Reliability of measures should be assessed and assured by a quality control program based on randomly selected duplicate assessments. Just as the power of a study is reported in a final publication, so also should the reliability of the outcome and eligibility measurements so as to allow the authors to better describe, and readers to better understand, the sources of imprecision in study results, and those who follow to improve the design of future trials.