Optimal Group Sequential Designs and Related (In Clinical Trials)

Group sequential designs for clinical trials.

Group sequential designs for stepped-wedge cluster randomised trials

BACKGROUND/AIMS The stepped-wedge cluster randomised trial design has received substantial attention in recent years. Although various extensions to the original design have been proposed, no guidance is available on the design of stepped-wedge cluster randomised trials with interim analyses. In an individually randomised trial setting, group sequential methods can provide notable efficiency ga...

A Restricted Class of Group Sequential Designs for Monitoring Clinical Trials

A feature of most group sequential designs is that the critical value at the final stage does not equal the critical value corresponding to a fixed sample design. This can lead to confusion when a seemingly significant sample statistic at the final stage fails to reject the null hypothesis. Two and three-stage designs are presented which allow acceptance, rejection, or continuation at the first...

Flexible sequential designs for multi-arm clinical trials.

Adaptive designs that are based on group-sequential approaches have the benefit of being efficient as stopping boundaries can be found that lead to good operating characteristics with test decisions based solely on sufficient statistics. The drawback of these so called 'pre-planned adaptive' designs is that unexpected design changes are not possible without impacting the error rates. 'Flexible ...

Asymptotic Optimal Sample Sizes for Discovering a Promising Treatment in Phase II Group Sequential Clinical Trials

We propose an asymptotic optimal procedure for determining the per-study sample size of a series of Phase II clinical studies. The sequence of studies seeks to discover an active treatment among a sequence of treatments under evaluation. Each phase II study proceeds in r stages with r=1, 2, or 3. Our result serves two practical purposes. First, it yields asymptotic optimal sample sizes. Second,...