Adaptive Group Sequential Trials with the Standardized Mean Difference as Effect Size

Abstract

In a thorough and extensive simulation study, we investigate the practical properties of repeated confidence intervals and point estimates for the standardized difference of normal means in adaptive group sequential trials. The theoretical foundations have been described in Hartung and Knapp (2009, 2010). In the simulation study, we consider an adaptive three-stage Pocock (1977)-type design for planning and showing noninferiority and an adaptive five-stage O'Brien-Fleming (1979)-type design for planning and showing superiority.