Adaptive Trials and Interim Analysis

This chapter discusses the important aspect of changing trial aspects, including analyzing data, before formal completion of a trial. Interim analysis (or analyses before trial is finished) should be planned and described in the study protocol, before starting the trial, to ensure the potential penalties for doing such analyses do not invalidate trial results and/or satisfy ethical requirements. The chapter discusses reasons and methods to perform interim analysis. Based on the results from interim analysis, some adjustments in the trial should be required, including early termination. Although the main goal of adaptive design is to increase the success of clinical development, making the studies more efficient and more likely to demonstrate the effect of a treatment, the investigator needs to be careful when using these methods as they can also introduce other potential biases in the study.