Gordon Guyatt
Physician who coined evidence-based medicine
Gordon Guyatt coined the phrase "evidence-based medicine" and co-developed the GRADE framework that NICE uses to rate research quality — the same framework underlying the Cass Review's damning verdict on gender medicine for children. His Beyond Gender appearance became a landmark: the architect of that evidence standard admitting he signed an advocacy statement endorsing the very treatments it condemns, without reading it.
Gordon Guyatt is Distinguished Professor of Health Research Methods, Evidence, and Impact at McMaster University, Canada, and the physician who in 1991 coined the phrase "evidence-based medicine." He co-developed the GRADE framework — the system for grading the quality of clinical evidence — which forms the backbone of NICE guidelines in Britain. When the Cass Review rated the evidence for puberty blockers and cross-sex hormones as "very low quality," it was using the very standards Guyatt helped build.
Guyatt's own systematic reviews of the evidence for paediatric gender interventions reached strikingly similar conclusions: the research base was weak and the claims made by gender clinics — including the former Tavistock GIDS — far outstripped what the data could support. For British parents and clinicians who watched the NHS close GIDS and commission an entirely new model of care, his findings carry particular weight: the father of the evidence standard is reading from the same page as Hilary Cass.
What makes his appearance in Gordon Guyatt's Confession: What the Father of Evidence-Based Medicine Didn't Read (episode 36, September 2025) so striking is the admission at its heart. Despite those research conclusions, Guyatt acknowledges signing a public advocacy statement that endorsed paediatric gender care — without having read it. Speaking with hosts Stella O'Malley, Mia Hughes, and Dr Bret Alderman, he reflects candidly on how scientific authority can be recruited to political ends.
For British listeners, the episode arrives at a charged moment. The NHS has overhauled gender services for young people — restricting puberty blockers to research settings — and debates over schools, safeguarding, and the Gender Recognition Act keep the underlying questions firmly on the national agenda. Guyatt's willingness to account for his own role in the advocacy landscape makes this one of the most significant conversations the podcast has produced.
