Reliability, effect size, and responsiveness of health status measures in the design of randomized and cluster-randomized trials
Reliability, effect size, and responsiveness of health status measures in the design of randomized and cluster-randomized trials
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DOI：
10.1016/j.cct.2004.11.014
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发表时间：
2005-02-01
影响因子：
2.2
通讯作者：
Yasui, Y
中科院分区：
文献类型：
--
作者：
Diehr, P;Chen, L;Yasui, Y
背景资料：新的健康状况调查工具通常通过其心理测量（测量）属性来描述，例如有效性，可靠性，效应大小和响应性。对于群集随机试验，另一个重要的统计量是群集内仪器的组内相关性（ICC）。使用更好的仪器的研究可以在更小的样本量下进行，但更好的仪器可能在美元、机会成本方面更昂贵，或由于较长仪器的响应负担而导致数据质量较差。我们根据数学模型定义了心理测量学统计，并检查了双样本测试的功效作为重测信度，效应大小，反应性，和仪器的组内相关性。我们研究了“成本效益”的使用一个项目与五个项目的测量心理健康status.Findings：测量误差的标准模型下，心理测量统计都是相同的错误术语的功能。它们也是估计它们的设置的函数-在随机试验中，功效是可靠性和样本量的函数，如果N增加，则不太可靠的仪器可以达到期望的功效。在群集随机试验中，可以通过增加每个治疗组的群集数量（通常是每个群集的人数）以及选择更可靠的工具来获得足够的功效。一项措施的心理健康状况可能是更符合成本效益比五项measurement.Conclusion：如果目标是诊断或转介个别患者，一个具有较高的效度和信度的工具是必要的。在样本量很大或很容易增加的情况下，任何有效的仪器都可能具有成本效益。许多已发表的心理测量学统计值很可能仅在与估计值相似的环境中才是准确的。(c)2004爱思唯尔公司All rights reserved.
Background: New health status survey instruments are often described by their psychometric (measurement) properties, such as Validity, Reliability, Effect Size, and Responsiveness. For cluster-randomized trials, another important statistic is the Intraclass Correlation (ICC) for the instrument within clusters. Studies using better instruments can be performed with smaller sample sizes, but better instruments may be more expensive in terms of dollars, opportunity cost, or poorer data quality due to the response burden of longer instruments.Methods: We defined the psychometric statistics in terms of a mathematical model, and examined the power of a two-sample test as a function of the test-retest Reliability, Effect Size, Responsiveness, and Intraclass Correlation of the instrument. We examined the "cost-effectiveness" of using a one-item versus a five-item measure of mental health status.Findings: Under the standard model for measurement error, the psychometric statistics are all functions of the same error term. They are also functions of the setting in which they were estimated-In randomized trials, power is a function of Reliability and sample size, and a less reliable instrument can achieve the desired power if N is increased. In cluster-randomized trials, adequate power may be obtained by increasing the number of clusters per treatment group (and often the number of persons per cluster), as well as by choosing a more reliable instrument. The one-item measure of mental health status may be more cost-effective than the five-item measure in some situations.Conclusion: If the goal is to diagnose or refer individual patients, an instrument with high Validity and Reliability is needed. In settings where the sample sizes are large or can be increased easily, any valid instrument may be cost-effective. It is likely that many published values of psychometric statistics are accurate only in settings similar to that in which they were estimated. (c) 2004 Elsevier Inc. All rights reserved.