Gordon Guyatt's Confession: What the Father of Evidence-Based Medicine Didn't Read (#36)
8 September 2025
With Gordon Guyatt
North America
Gordon Guyatt, who coined the term evidence-based medicine, led systematic reviews rating the quality of evidence for paediatric gender interventions as low — findings consistent with formal health technology assessments across Sweden, Finland, England, Denmark and Norway. In this interview he admits co-signing a public statement endorsing youth gender medicine as medically necessary without reading it carefully. The episode exposes the gap between rigorous methodology and public advocacy, and asks what happens when the tools of evidence-based medicine are selectively deployed on both sides of a contested debate.
Gordon Guyatt coined the phrase "evidence-based medicine" in 1991 and built the conceptual architecture — the hierarchy of evidence, the systematic review, the critical appraisal framework — that now governs clinical decision-making worldwide. As a professor at McMaster University in Canada, he also produced the training materials that generations of physicians use to distinguish robust evidence from weak. When that methodological pedigree is applied to paediatric gender medicine, the findings carry particular authority. His team's systematic reviews rated the quality of evidence for medical interventions in gender-dysphoric youth — puberty blockers, cross-sex hormones, surgical procedures — as low. That conclusion has been cited by legislators in twenty American states as grounds for restricting access to such treatments. It is broadly consistent with the findings of formal health technology assessments in Sweden, Finland, England, Denmark and Norway, each of which has restricted or paused youth gender treatment pathways on comparable evidentiary grounds over the same period. What makes this interview striking is a separate admission. Asked about a public statement he had co-signed endorsing what it called "medically necessary care for gender diverse youth," Guyatt acknowledged he had not read the relevant passage carefully. "That was not my paragraph, and I didn't read carefully enough," he explains. "I was a dope." The admission illustrates a recurring problem in this debate: researchers whose own methodology points towards caution can find themselves publicly aligned with advocacy positions that go considerably further than their evidence supports. Throughout the conversation Guyatt also insists he is "a total non-expert" in paediatric gender medicine specifically. When pressed on whether adolescents can give meaningful informed consent to interventions affecting their future fertility, he deflects to analogies drawn from elderly patients with cognitive impairment. A paediatric endocrinologist cited in the episode describes discussing fertility preservation with a fourteen-year-old as "like talking to a blank wall." Guyatt dismisses this as a single anecdote, while his own counter-position rests, by his account, on personal impressions from conversations. The episode also revisits the historical parallel of high-dose chemotherapy with autologous bone marrow transplantation for breast cancer. Patient activism and media coverage drove that treatment into widespread use before randomised controlled trials demonstrated it offered no advantage over standard care and caused serious harm in some cases. The structural features of that episode — advocacy pressure outpacing evidence, and institutional reluctance to maintain scepticism — are ones that several European health review bodies have cited explicitly when explaining their decisions to pause paediatric gender pathways. That the man who built the methodological tools for evaluating such decisions also signed documents he had not read is an uncomfortable reminder that scientific rigour and institutional behaviour do not always travel together.
