Department of Epidemiology and Biostatistics and Robarts Clinical Trials of Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada.
Stat Med. 2012 Dec 20;31(29):3972-81. doi: 10.1002/sim.5466. Epub 2012 Jul 4.
The number of subjects required to estimate the intraclass correlation coefficient in a reliability study has usually been determined on the basis of the expected width of a confidence interval. However, this approach fails to explicitly consider the probability of achieving the desired interval width and may thus provide sample sizes that are too small to have adequate chance of achieving the desired precision. In this paper, we present a method that explicitly incorporates a prespecified probability of achieving the prespecified width or lower limit of a confidence interval. The resultant closed-form formulas are shown to be very accurate.
在可靠性研究中，估计组内相关系数所需的样本量通常是基于置信区间的预期宽度来确定的。然而，这种方法没有明确考虑达到期望区间宽度的概率，因此可能会提供太小的样本量，以至于没有足够的机会达到所需的精度。在本文中，我们提出了一种方法，该方法明确地纳入了达到预定置信区间宽度或下限的预定概率。结果表明，所得的闭式公式非常准确。
