Rick Chappell, Professor, Departments of Statistics and of Biostatistics and Medical Informatics at the University of Wisconsin – Madison, will present:

“Modern Controversies over Survival Outcomes in Clinical Trials”

Textbooks describing how to analyze time-to-event outcomes in clinical trials tend to list a limited range of topics. Differences are often quantified using hazard ratios from the Cox model and its associated score, the log-rank test. Weighted rank tests may be presented, along with comparisons of landmarks and quantiles. All these have their disadvantages in terms of interpretation, convenience, and/or power. Furthermore, cancer immunotherapy and many other treatments in a variety of diseases can have delayed effects causing pairs of curves to diverge after months or years of followup. In such cases the log-rank test’s power will be low and the associated hazard ratio estimate uninterpretable. Rank tests with increasing weights suffer from the paradoxical property of rewarding early failures. I will discuss various available alternatives including some which are quite new.

A seminar tea will be held at 11:00 a.m. in University Office Plaza, Room 240. All are Welcome.