# 9.9 - Summary

In this lesson, among other things, we learned:

- Differentiate between valid and invalid reasons for interim analyses and early termination of a trial.
- Identify characteristics of a sound plan for interim analysis.
- Understand the theoretical framework for a likelihood based interim analysis.
- Compare and contrast the Bayesian approach to analysis with the frequentist approach.
- Recognize the general effects of the choice the prior on the posterior probability distribution from a Bayesian analysis.
- Compare α spending functions for 3 group sequential methods for interim analysis.
- Comment on the use of a group sequential method in a published statistical analysis.
- Recognize a futility assessment and define conditional power.
- List topics that should be covered in an interim report to an IRB.
- List the advantages and disadvantages of a DSMB and describe who might compose the DSMB.
- List the issues of concern to a DSMB in a typical clinical study.