TY - JOUR N1 - © The Author 2025. This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY 4.0) license (http://creativecommons.org/licenses/by/4.0/). TI - Guidance for protocol content and reporting of factorial randomised trials: explanation and elaboration of the CONSORT 2010 and SPIRIT 2013 extensions VL - 388 AV - public Y1 - 2025/// JF - BMJ A1 - Kahan, Brennan C A1 - Juszczak, Edmund A1 - Beller, Elaine A1 - Birchenall, Megan A1 - Chan, An-Wen A1 - Hall, Sophie A1 - Little, Paul A1 - Fletcher, John A1 - Golub, Robert M A1 - Goulao, Beatriz A1 - Hopewell, Sally A1 - Islam, Nazrul A1 - Zwarenstein, Merrick A1 - Elbourne, Diana A1 - Montgomery, Alan ID - discovery10204508 UR - https://doi.org/10.1136/bmj-2024-080785 PB - BMJ ER -