Bayesian Priors in Clinical Trials: Why Historical Borrowing Reduces Sample Size
A simulation study on why historical control borrowing reduces sample size, and what happens when the history is wrong
Bayesian Clinical Trials
The Simulations Behind Comment 3
Last week I published what I submitted to the FDA on their January 2026 Bayesian guidance. Comment 3 argued that when you compose Bayesian trial components (priors, borrowing, sequential monitoring), the system's operating characteristics can diverge from what component-level analysis predicts. This post shows you the math. The
The COVID-19 Vaccine Trial That Put Bayesian Sequential Design on the Map
When the Pfizer/BioNTech BNT162b2 trial reported 95% efficacy in November 2020, the world saw a scientific triumph. What most people missed, and what many statisticians still underappreciate, is that the trial's primary analysis was Bayesian. Not frequentist group sequential boundaries. Not O'Brien-Fleming. A posterior probability