Contents
Why group sequential design?
In these designs, groups of observations are collected and repeatedly analyzed, while controlling error rates. Compared to a fixed sample size design, where data is analyzed only once, group sequential designs offer the possibility to stop the study at interim looks at the data either for efficacy or futility.
What is futility boundary?
A futility boundary (futility stopping boundary, rarely futility limit) is a statistical decision boundary used in sequential testing such as an AGILE A/B test. It is built in such a way that it maintains the type II error probability (beta β) larger than a specified level, on average.
What is futility criteria?
The term ‘futility’ is used to refer to the inability of a clinical trial to achieve its objectives. In particular, stopping a clinical trial when the interim results suggest that it is unlikely to achieve statistical significance can save resources that could be used on more promising research.
What is non binding futility?
In clinical trial applications non-binding futility boundaries are usually applied because they allow reacting flexibly to interim results such as adverse events or new external information.
What is sequential design?
Sequential designs are developmental research designs that include elements of both cross-sectional and longitudinal studies; they are configured in ways to address confounds between age, cohort, and time of measurement.
What is exercise in futility?
: an activity that is not successful or worthwhile The negotiations turned out to be an exercise in futility.
When to stop for futility in group sequential designs?
In the context of group sequential designs, it can generally be differentiated between binding and non-binding stopping for futility rules, compare also Bretz et al [ 26 ]. ‘Binding’ means that stopping for futility at the interim analysis is obligatory whenever the futility criteria are met.
When to stop a trial in group sequential design?
In contrast, group sequential designs allow an early stopping of the trial at interim, either for efficacy when the treatment effect is significant or for futility when the treatment effect seems too small to justify a continuation of the trial.
What do you call a group sequential design?
For this reason, so-called ‘group sequential designs’ are of particular importance in this setting.
Are there any binding rules for futility stopping?
Among futility stopping methods of group sequential designs, two main rules are discussed in the literature. Futility stopping rules can either be binding or non-binding, where binding means that stopping is mandatory if the criterion is met and non-binding means that the investigator can freely decide if he or she really wants to stop.