Point estimation following group sequential tests.

Kim and DeMets (1987, Biometrics 43, 857-864) described an exact procedure for constructing confidence intervals for a normal mean following group sequential tests when the boundaries were generated based on the notion of use functions proposed by Lan and DeMets (1983, Biometrika 70, 659-663). In this article, three point estimators for a normal mean following group sequential tests are considered, and their properties are investigated by Monte Carlo simulation. Based on the simulation results, some suggestions are made as to the choice of group sequential designs and use function.