Bayesian sequential analysis of adverse events with binary data

We propose a Bayesian Sequential procedure to test hypotheses concerning the Relative Risk between two specific treatments based on the binary data obtained from the two-arm clinical trial. Our development is based on the optimal sequential test of \citet{wang2024early}, which is cast within the Bayesian framework. This approach enables us to provide, in a straightforward manner based on the Stopping Rule Principle (SRP), an assessment of the various error probabilities via posterior probabilities and conditional error probabilities. Additionally, we present the connection to the notion of the Uniformly Most Powerful Bayesian Test (UMPBT). To illustrate our procedure, we utilized the data from \citet{silva2020optimal} to analyze the results obtained from the standard Bayesian and the modified Bayesian test of \citet{berger1997unified} under several different prior distributions of the parameters involved.