O'Gorman T W, Woolson R F, Jones M P
Department of Mathematical Sciences, Northern Illinois University, DeKalb 60115.
Control Clin Trials. 1994 Apr;15(2):135-53. doi: 10.1016/0197-2456(94)90017-5.
In this paper, we compare two methods of estimating the difference between the proportion of adverse events in a test treatment group and the proportion of adverse events in a control treatment group in a multicenter clinical trial. We used simulated data to compare the bias and mean squared error of the weighted least squares estimator to the bias and mean squared error of the Cochran-Mantel-Haenszel estimator. We also computed the coverage probabilities for confidence intervals derived from these estimators. We found that the weighted least squares method was often seriously biased. The coverage probabilities for the Cochran-Mantel-Haenszel estimators were often closer to their nominal values than were the coverage probabilities for the weighted least squares estimators. It also was found that these methods require a larger sample size to maintain coverage probabilities near their nominal values when unequal numbers of persons are assigned to the test and control treatments.
在本文中，我们比较了在多中心临床试验中估计试验治疗组不良事件比例与对照治疗组不良事件比例差异的两种方法。我们使用模拟数据来比较加权最小二乘估计器的偏差和均方误差与 Cochr an - Mantel - Haenszel 估计器的偏差和均方误差。我们还计算了由这些估计器得出的置信区间的覆盖概率。我们发现加权最小二乘法常常存在严重偏差。Cochran - Mantel - Haenszel 估计器的覆盖概率通常比加权最小二乘估计器的覆盖概率更接近其名义值。还发现，当分配到试验组和对照组的人数不相等时，这些方法需要更大的样本量才能使覆盖概率维持在其名义值附近。
