The estimands framework: a primer on the ICH E9(R1) addendum.

Competing Interests: Competing interests: All authors have completed the ICMJE uniform disclosure form at https://www.icmje.org/disclosure-of-interest/ and declare: support from the UK Medical Research Council and the NIHR for the submitted work. BCK and SC declare grant funding (payable to employing institutions) from the MRC-NIHR Trials Methodology Research Partnership. BCK and ME declare grant funding (payable to employing institutions) from the NIHR for the FLO-ELA trial. TPM declares consultancy fees from Bayer Healthcare Pharmaceuticals, Alliance Pharmaceuticals, Gilead Sciences, and Kite Pharma; declares conference attendance and travel paid for as an invited speaker at the 2023 European Society for Blood and Marrow Transplantation conference; and is an independent member of the data and safety monitoring board for the FLO-ELA trial. All other authors declare no conflicts of interest.