Multi-outcome trials with a generalised number of efficacious outcomes

TL;DR

This paper introduces multi-stage, multi-outcome trial designs that evaluate any number of promising outcomes, extending previous methods limited to two outcomes and single-stage approaches.

Contribution

It proposes novel group-sequential and drop-the-losers designs that handle multiple outcomes in a multi-stage setting, allowing for any number of outcomes.

Findings

Designs accommodate any number of outcomes

Extend multi-outcome trials to multi-stage settings

Allow for flexible outcome evaluation

Abstract

Existing multi-outcome designs focus almost entirely on evaluating whether all outcomes show evidence of efficacy or whether at least one outcome shows evidence of efficacy. While a small number of authors have provided multi-outcome designs that evaluate when a general number of outcomes show promise, these designs have been single-stage in nature only. We therefore propose two designs, of group-sequential and drop the loser form, that provide this design characteristic in a multi-stage setting. Previous such multi-outcome multi-stage designs have allowed only for a maximum of two outcomes; our designs thus also extend previous related proposals by permitting any number of outcomes.