Shan Guogen, Bernick Charles, Banks Sarah
Epidemiology and Biostatistics Program, Department of Environmental and Occupational Health, School of Community Health Sciences, University of Nevada Las Vegas, Nevada, USA.
Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, Nevada, USA.
Br J Math Stat Psychol. 2018 Feb;71(1):60-74. doi: 10.1111/bmsp.12107. Epub 2017 Jun 30.
This research was motivated by a clinical trial design for a cognitive study. The pilot study was a matched-pairs design where some data are missing, specifically the missing data coming at the end of the study. Existing approaches to determine sample size are all based on asymptotic approaches (e.g., the generalized estimating equation (GEE) approach). When the sample size in a clinical trial is small to medium, these asymptotic approaches may not be appropriate for use due to the unsatisfactory Type I and II error rates. For this reason, we consider the exact unconditional approach to compute the sample size for a matched-pairs study with incomplete data. Recommendations are made for each possible missingness pattern by comparing the exact sample sizes based on three commonly used test statistics, with the existing sample size calculation based on the GEE approach. An example from a real surgeon-reviewers study is used to illustrate the application of the exact sample size calculation in study designs.
本研究受一项认知研究的临床试验设计所驱动。该初步研究采用配对设计，其中存在一些数据缺失的情况，具体而言，缺失数据出现在研究末尾。现有的确定样本量的方法均基于渐近方法（例如广义估计方程（GEE）方法）。当临床试验中的样本量为小到中等时，由于I型和II型错误率不尽人意，这些渐近方法可能并不适用。因此，我们考虑采用精确无条件方法来计算具有不完整数据的配对研究的样本量。通过比较基于三种常用检验统计量的精确样本量与基于GEE方法的现有样本量计算结果，针对每种可能的缺失模式给出了建议。来自一项真实的外科医生评审员研究的示例用于说明精确样本量计算在研究设计中的应用。
