Borrowing of information from historical or external data to inform inference in a current trial is an expanding field in the era of precision medicine, where trials are often performed in small patient cohorts for practical or ethical reasons. Many approaches for borrowing from external data have been proposed. Even though these methods are mainly based on Bayesian approaches by incorporating external information into the prior for the current analysis, frequentist operating characteristics of the analysis strategy are of interest. In particular, type I error and power at a prespecified point alternative are in the focus. It is well-known that borrowing from external information may lead to the alteration of type I error rate. We propose a procedure to investigate and report the frequentist operating characteristics in this context. The approach evaluates type I error rate of the test with borrowing from external data and calibrates the test without borrowing to this type I error rate. On this basis, a fair comparison of power between the test with and without borrowing is achieved.

翻译：在精准医学时代，由于实践或伦理原因，试验通常在小规模患者队列中进行，从历史数据或外部数据借用信息以指导当前试验的推断是一个不断发展的领域。已有许多借用外部数据的方法被提出。尽管这些方法主要基于贝叶斯方法，通过将外部信息纳入当前分析的先验分布中，但分析策略的频率主义操作特征同样值得关注。特别是，预先指定点备择假设下的I类错误率和检验功效是重点。已知借用外部信息可能导致I类错误率发生改变。我们提出了一种程序，用于在此背景下研究和报告频率主义操作特征。该方法评估了借用外部数据检验的I类错误率，并将未借用数据的检验校准至该I类错误率水平。在此基础上，实现了对借用与未借用数据检验之间检验功效的公平比较。