Inference in group sequential designs with causal mechanisms: implications for power and mediation analysis.

ABSTRACT:

Background

Group sequential designs are increasingly employed to allow trials to stop early with statistical rigor. While existing work focuses on intention-to-treat effect on clinical endpoints, the properties of mediation analysis (commonly conducted in psychological trials to understand a causal mechanism) remain unknown under group sequential designs.

Methods

Considering a group sequential design with one interim analysis for early stopping for efficacy, we conduct a simulation study to evaluate existing analysis techniques when the treatment effect on a continuous outcome is partially or fully mediated by a continuous intermediate variable measuring a casual mechanism. We study the probability of rejecting the null hypotheses on the total effect (i.e., intention-to-trea

SUBMITTER: Lee KM 

PROVIDER: S-EPMC12619153 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature