Early secondary outcome analysis in multi-phase randomised-controlled trials, a pragmatic approach: the Healthy Life Trajectories Initiative (HeLTI)

BACKGROUND: The extended time frame of some trials can cause significant challenges in delaying all analyses until the primary outcome is attained. This may particularly affect any mechanistic studies linked to secondary outcomes, as well as impact the involvement of trainees and junior investigators in the project. This manuscript describes the strategy and process by which the leadership of the Healthy Life Trajectories Initiative (HeLTI) developed an analysis approach. METHODS: The study involved the engagement of an expert panel with broad knowledge in disciplines relevant to the study. RESULTS: Several reviewers emphasised the importance of undertaking analysis only after the primary outcome has been achieved. However, the majority of reviewers highlighted that this was not practical in the context of the HeLTI consortium because valuable interim analysis would be missed. CONCLUSION: After careful consideration of the issue and feedback received, the HeLTI leadership agreed to an approach that allowed publishing between-group comparisons of secondary outcomes and linked mechanistic studies before the primary outcome, using an a priori agreed phased approach.