Different Clinical Questions Need Different Estimands

The ICH E9(R1) estimands framework requires precise specification of the treatment effects (estimands) a trial is designed to estimate. A recent article by Troxel et al. [1] has advanced a narrow view that only estimands using the treatment-policy strategy are scientifically defensible. In particular, the article recommends that journals adopt a new policy with regard to reporting results from clinical trials, advocating that only results based on the treatment policy strategy should appear in the main body of the paper with estimates based on other strategies relegated to supplementary materials. Treatment-policy estimands target the effect of assignment to treatment and are defined to include outcomes after non-terminal post-randomization events, such as treatment discontinuation or initiation of alternative or rescue medications. Use of this estimand requires that outcome collection continues following these intercurrent events. In the presence of missing data, estimation of effects using the treatment policy strategy typically relies on strong, unverifiable assumptions [2]. While using treatment policy strategies to address all intercurrent events is appropriate for certain scientific objectives, these estimands do not address all clinically relevant questions. Results based on estimands using alternative strategies for primary and key secondary objectives should therefore also be presented in the main body of the published paper when they address important clinical questions that are relevant to patient care or decision-making.