New guidance on the use of estimands

23 Jan 2024

Researchers at the MRC Clinical Trials Unit at UCL have developed new guidance to help other researchers better understand how to use estimands in their studies, to improve the interpretation and utility of trial results. The paper was published in the BMJ today.  

An estimands is a description of the research question a trial seeks to answer. They provide a clear way to communicate treatment effects to stakeholders, and their use can help researchers better understand how their study should be designed and analysed. But despite recent regulatory guidance requiring their use, uptake of estimands is slow, with lack of familiarity with key terms and concepts acting as a key barrier.  

“Estimands can help researchers ensure their studies are appropriately designed to meet stakeholder needs,” says first author Brennan Kahan, Principal Research Fellow at the MRC CTU at UCL, who led the work. “However, the concepts and terminology are new for many people and uptake has been slow. Our work helps to bridge this gap, by explaining these concepts, and providing practical guidance showing how estimands can be used to guide study design.”   

This publication provides an overview of the estimands framework, with guidance on terminology and concepts. It also includes practical examples of using estimands to decide how study’s should be appropriately designed and analysed.  

Further information:

• The estimands framework: a primer on the ICH E9(R1) addendum paper in the BMJ
• 'We must let the research question drive study methods' opinion piece in the BMJ
• Our work on methods for clinical trials analysis