Applying Bayesian ideas in drug development and clinical trials.

The Bayesian paradigm emphasizes that studies are not performed in isolation, and that external evidence can be used formally in the design, monitoring and reporting of clinical trials. A variety of tools for assessing the current evidence for treatment efficacy are presented, making use of graphical display to provide insight into ethical and efficiency issues in starting and stopping trials--these are illustrated with a trial in osteosarcoma that is currently taking place. Finally we recommend that an additional 'interpretation' section is placed in clinical reports to provide a bridge between 'results' and 'discussion'--it is this section that would contain the Bayesian perspective.