Discussion on "A Hybrid Selection and Testing Procedure with Curtailment for Comparative Clinical Trials" by Elena M. Buzaianu and Pinyuen Chen.

Buzaianu and Chen apply strong curtailment to modify the two-stage select-and-test clinical trial design proposed by Thall et al. (1988). The modification reduces the expected sample size while maintaining overall power but requires continuous monitoring in stage 1. I will review the history of this type of design and discuss practical issues related to the use of strong curtailment that arise in trial conduct.