Equal Marginal Power for Co-Primary Endpoints

TL;DR

This paper introduces a method to ensure equal marginal power across co-primary endpoints in randomized trials by leveraging multiple testing procedures, improving study design and operating characteristics.

Contribution

It proposes a novel approach to achieve equal marginal power for co-primary endpoints using flexible multiple testing procedures, addressing a gap in current guidance.

Findings

Method successfully equalizes marginal power across endpoints.

Comparison shows improved study design and operating characteristics.

Provides practical guidance for sample size determination.

Abstract

The choice of sample size in the context of co-primary endpoints for a randomised trial is discussed. Current guidance can leave endpoints with unequal marginal power. A method is provided to achieve equal marginal power by using the flexibility provided in multiple testing procedures. A comparison is made to several choices of rule to determine the sample size, in terms of the study design and its operating characteristics.