Clinical Trials

■■❚❙❘Chapter 31Interim Monitoringand Stopping RulesJames F Lymp, Stephen L Kopecky,Ameet Bakhai, and Duolao WangInterim monitoring has, for a variety of reasons, becomeincreasingly important and common in clinical trials. Ethicalconsiderations require that patient safety be monitored andthat decisions regarding treatment benefit, or lack thereof,be made as quickly as possible. However, care must be takennot to jump to early conclusions based on limited evidence. Asa consequence, many statistical methods have been developedfor the design of clinical trials, and these methods account forthe interim monitoring process. In this chapter, we discuss themotivations for interim monitoring, show how inappropriatestatistical methods can lead to erroneous conclusions, andpresent an outline of some statistical methods that can beused for appropriate interim monitoring in clinical trials.353