Abstract

Some clinical trials in ophthalmology or dermatology randomize patients into two or more treatment groups, and observations are made for one or more anatomical regions (or sites) for each patient. In this case, patients are primary sampling units, and their responses for multiple anatomical sites are usually correlated. Useful randomization-based extensions of the Cochran–Mantel–Haenszel method are discussed here for such studies; and aspects of their application are illustrated with two examples. The first example is a randomized ophthalmology clinical trial with the number of treated eyes as strata and a dichotomous response criterion. The second example is a randomized dermatology clinical trial with three strata for the number of treated anatomical regions among the face, scalp, or chest, one covariable (as disease severity at baseline), and a dichotomous outcome. For these examples, the results are interpretable through the proportions of treated sites with favorable outcome for each treatment and their difference between treatments.

摘要

眼科或皮肤科的一些临床试验将患者随机分为两个或多个治疗组，并对每个患者的一个或多个解剖区域（或部位）进行观察。在这种情况下，患者是初级抽样单位，他们对多个解剖部位的反应通常是相关的。对于此类研究，此处讨论了 Cochran-Mantel-Haenszel 方法的有用的基于随机化的扩展；并用两个例子说明了它们的应用方面。第一个例子是随机眼科临床试验，以治疗眼的数量为层次和二分响应标准。第二个例子是一项随机皮肤病临床试验，对面部、头皮或胸部中治疗的解剖区域数量有三个层次，一个协变量（作为基线疾病严重程度），和二分结果。对于这些示例，结果可以通过对每种治疗具有良好结果的治疗部位的比例及其治疗之间的差异来解释。