Group-sequential response-adaptive designs for censored survival outcomes

Adaptive Designs for Group Sequential Clinical Survival Experiments

Randomized two-group clinical survival experiments now commonly allow at least one interim look, enabling possible early stopping to meet ethical concerns. Various authors have also studied the possibility of interim design modifications to adapt to unexpected accrual or control-group mortality rates. This paper formulates trial design as a decision theoretic problem with a finite number of int...

Exact inference for adaptive group sequential designs.

Methods for controlling the type-1 error of an adaptive group sequential trial were developed in seminal papers by Cui, Hung, and Wang (Biometrics, 1999), Lehmacher and Wassmer (Biometrics, 1999), and Müller and Schäfer (Biometrics, 2001). However, corresponding solutions for the equally important and related problem of parameter estimation at the end of the adaptive trial have not been complet...

Issues in Group Sequential/Adaptive Designs

In recent years, there has been great interest in the use of adaptive features in clinical trials (i.e., changes in design or analyses guided by examination of the accumulated data at an interim point in the trial) that may make the studies more efficient (e.g., shorter duration, fewer patients). Many statistical methods have been developed to maintain the validity of study results when adaptiv...

From Group Sequential to Adaptive Designs

Group sequential designs for clinical trials.