Estimands and Missing Data Working Group Activity / Deliverables
Chairs: Elena Polverejan, PhD; Lorenzo Guizzaro, MD, PhD
Upcoming Activity: Working Group Session – 22nd Annual Scientific Meeting, 18-20 February 2026, Washington DC
The ICH E9(R1) Addendum on “Estimands and Sensitivity Analysis in Clinical Trials” (2019) introduced a framework that is still being fully integrated across clinical trials. In 2026, the final ICH M11 protocol template will mandate defining estimands in Section 3, making collaboration between statistical and non-statistical functions more critical than ever.
The ISCTM Estimands and Missing Data Working Group (WG) – comprising clinicians and statisticians from FDA, EMA, and industry – has developed practical approaches for implementing this framework, published in 2023 and presented at prior ISCTM meetings. Building on this work, this WG meeting will focus on strategies for effective multi-disciplinary collaboration when selecting estimands, using clear, clinically meaningful language. In particular, the design of psychedelic trials requires a re-thinking of the clinical question to be answered and events that can happen after treatment assignment. Examples from depression and psychedelic research will be used as illustration in this session.
Most importantly, the WG seeks input from the ISCTM community: What challenges have you faced in applying the estimand framework? How can we improve collaboration across disciplines? Join us to share experiences and shape best practices for the future.
Most Recent Activity: Working Group Session – 21st Annual Scientific Meeting, 19-21 February 2025, Washington DC – View Summary
While the ICH E9(R1) Addendum on “Estimands and Sensitivity Analysis in Clinical Trials” was released in 2019, the widespread implementation of defining and reporting estimands across all clinical trials is still in progress and the engagement of non-statistical
functions in this process is still to be fully experienced. The ISCTM Estimands and Missing Data Working Group (WG) consists of both clinicians and statisticians from FDA, EMA and the Pharma Industry. This WG developed an interdisciplinary process for implementing the estimand framework with multiple estimand example, which was published in 2023 (see link for Polverejan et al 2023 at https://isctm.org/publications/). This WG also organized a session on estimands at the 20th Annual Scientific Meeting (see slides and recording at https://isctm.org/meeting/20th-annual-scientific-meeting/). In this session, the WG will provide a refresh of the process of implementing the estimand framework and share the key messages from the 2024 estimand session. Future collaboration with the Psychedelics WG will also be discussed. Most importantly, the WG would like to learn of any challenges or issues that the ISCTM community has encounter when applying the estimand framework.
Publications:
Defining Clinical Trial Estimands: A Practical Guide for Study Teams with Examples Based on a Psychiatric Disorder, Therapeutic Innovation & Regulatory Science (open access)
Activity History:
Session- How to Implement the Estimand Framework in Clinical Trials – Examples, Examples, Examples, 20th Annual Scientific Meeting, 21-23 February 2024, Washington DC
Working Group Session – 19th Annual Scientific Meeting – 15-17 February 2023, Washington DC – View Summary
Working Group Session – 18th Annual Scientific Meeting – View Slides – 23-25 February 2022, Washington DC
Working Group Session – 17th Annual Scientific Meeting-View Summary– 7 April 2021, Virtual
Working Group Session – 16th Annual Scientific Meeting-View Summary– 19 February 2020, Washington DC
Working Group Session – 15th Annual Scientific Meeting- View Slides – 19 February 2019, Washington DC
Working Group Session – 14th Annual Scientific Meeting-View Summary – 20 February 2018, Washington DC
13th Annual Meeting – 21 February 2017 – Washington DC
Inaugural Working Group Session
Working group session was borne out of the Missing Data session presented at the 2016 Autumn Conference-View Meeting Presentations/Videos
Link to Estimands & Missing Data Project Materials