|Event Title||Biostatistics Seminar Series - Bayesian clinical trial design|
|Sponsor||NC TraCS (Translational and Clinical Sciences) Institute: NIH CTSA at UNC-CH|
|Date/Time||11/06/2020 10:30 AM - 12:00 PM|
In the third and final session of the NC TraCS Biostatistics Fall 2020 Seminar series, we consider the problem of Bayesian sample size determination for a clinical trial in the presence of historical data that inform the treatment effect. Our broadly applicable, simulation-based methodology provides a framework for calibrating the informativeness of a prior while simultaneously identifying the minimum sample size required for a new trial such that the overall design has appropriate power to detect a non-null treatment effect and reasonable type I error control. We develop a comprehensive strategy for eliciting null and alternative sampling prior distributions which are used to define Bayesian generalizations of the traditional notions of type I error control and power. Bayesian type I error control requires that a weighted-average type I error rate not exceed a prespecified threshold. We develop a procedure for generating an appropriately sized Bayesian hypothesis test using a simple partial-borrowing power prior which summarizes the fraction of information borrowed from the historical trial. We present results from simulation studies that demonstrate that a hypothesis test procedure based on this simple power prior is as efficient as those based on more complicated meta-analytic priors, such as normalized power priors or robust mixture priors, when all are held to precise type I error control requirements. We demonstrate our methodology using a real data set to design a follow-up clinical trial with time-to-event endpoint for an investigational treatment in high-risk melanoma.
The NC TraCS Biostatistics Seminar Series provides more in-depth discussion of select biostatistical topics for clinical and translational researchers who have basic quantitative training in biostatistical methods. Join us this fall for seminars on data visualization & statistical graphics, power analysis & sample size planning, and Bayesian clinical trial design.
Presenter: Joeseph Ibrahim, PhD
UNC Department of Biostatistics