Arundel, CatherineClark, LauraParker, AdwoaBeard, David JColeman, ElizabethCooper, CindyDevane, DeclanEldridge, SandraGalvin, SandraGillies, KatieHewitt, Catherine ESutton, ChristopherTorgerson, David J.Treweek, Shaun2024-03-132024-03-132024-03-12Arundel, C, Clark, L, Parker, A, Beard, D J, Coleman, E, Cooper, C, Devane, D, Eldridge, S, Galvin, S, Gillies, K, Hewitt, C E, Sutton, C, Torgerson, D J & Treweek, S 2024, 'Trial Forge Guidance 4 : A guideline for reporting the results of randomised Studies Within A Trial (SWATs)', Trials, vol. 25, no. 1, 183. https://doi.org/10.1186/s13063-024-08004-01745-6215ORCID: /0000-0001-7890-2854/work/155729406ORCID: /0000-0002-7239-7241/work/186968380https://hdl.handle.net/2164/23008Acknowledgements We would like to thank those members of the PROMETHEUS programme who are not explicitly named as authors of this publication, but who provided valuable input to the delivery and conduct of the programme within which the guideline development sat. PROMETHEUS programme members include co-authors CA, LK, AP, DB, CC, DD, SG, KG, CH, CS, DT, and ST and P Bower (University of Manchester), L Culliford (University of Bristol), L Doherty (University of York), and R Emsley (Kings College London). We would like to thank public contributors who provided input and comment on earlier versions of this work. We would also like to thank the authors of the previous guidelines for reporting of embedded recruitment trials for their advice and input in the early stages of guideline development and to the independent reviewers and trialists who offered comments and piloting of the draft guideline. Funding Development of the SWAT reporting guideline was initiated as part of The PROMoting THE Use of SWATs (PROMETHEUS) programme, funded by the Medical Research Council (MRC) [grant number MR/R013748/1].11987764engStudy Within A TrialSWATEmbedded randomised controlled trialreporting guidelinereporting standardR MedicineMedical Research Council (MRC)MR/R013748/1RJournal article10.1186/s13063-024-08004-0251