Sommer Harriet, Wolkewitz Martin, Schumacher Martin
Institute for Medical Biometry and Statistics, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany.
Pharm Stat. 2017 Jul;16(4):267-279. doi: 10.1002/pst.1809. Epub 2017 Jun 9.
A variety of primary endpoints are used in clinical trials treating patients with severe infectious diseases, and existing guidelines do not provide a consistent recommendation. We propose to study simultaneously two primary endpoints, cure and death, in a comprehensive multistate cure-death model as starting point for a treatment comparison. This technique enables us to study the temporal dynamic of the patient-relevant probability to be cured and alive. We describe and compare traditional and innovative methods suitable for a treatment comparison based on this model. Traditional analyses using risk differences focus on one prespecified timepoint only. A restricted logrank-based test of treatment effect is sensitive to ordered categories of responses and integrates information on duration of response. The pseudo-value regression provides a direct regression model for examination of treatment effect via difference in transition probabilities. Applied to a topical real data example and simulation scenarios, we demonstrate advantages and limitations and provide an insight into how these methods can handle different kinds of treatment imbalances. The cure-death model provides a suitable framework to gain a better understanding of how a new treatment influences the time-dynamic cure and death process. This might help the future planning of randomised clinical trials, sample size calculations, and data analyses.
在治疗重症传染病患者的临床试验中使用了多种主要终点,现有指南并未给出一致的建议。我们建议在一个综合的多状态治愈-死亡模型中同时研究两个主要终点,即治愈和死亡,以此作为治疗比较的起点。这种技术使我们能够研究患者治愈和存活相关概率的时间动态变化。我们描述并比较了适用于基于该模型进行治疗比较的传统方法和创新方法。使用风险差异的传统分析仅关注一个预先指定的时间点。基于受限对数秩的治疗效果检验对有序的反应类别敏感,并整合了反应持续时间的信息。伪值回归提供了一个直接的回归模型,用于通过转移概率的差异来检验治疗效果。应用于一个实际数据实例和模拟场景,我们展示了这些方法的优缺点,并深入了解它们如何处理不同类型的治疗不平衡。治愈-死亡模型提供了一个合适的框架,有助于更好地理解新治疗如何影响时间动态的治愈和死亡过程。这可能有助于未来随机临床试验的规划、样本量计算和数据分析。