Manyara A, Davies P, Stewart D, Weir C, Young A, Blazeby J, Butcher N, Bujkiewicz S, Chan A, Dawoud D, Offringa M, Ouwens M, Hróbjartsson A, Amstutz A, Bertolaccini L, Bruno V, Devane D, Faria C, Gilbert P, Harris R, Lassere M, Marinelli L, Markham S, Powers J, Rezaei Y, Richert L, Schwendicke F, Tereshchenko L, Thoma A, Turan A, Worrall A, Christensen R, Collins G, Ross J, Taylor R, Ciani O. Reporting of surrogate endpoints in randomised controlled trial protocols (SPIRIT-Surrogate): extension checklist with explanation and elaboration. The BMJ 2024, 386: e078525. PMID: 38981624, PMCID: PMC11231880, DOI: 10.1136/bmj-2023-078525.Peer-Reviewed Original Research