This article originally appeared in Without Diminishment.
By Roy Eappen, November 18, 2025
A medical research icon’s backpedalling of his reviews on “gender-affirming care” highlights a vital facet of evidence-based medicine, it depends on practitioners standing by their findings in the face of activist pushback.
On Aug. 14, a group of five researchers including Gordon Guyatt, the father of evidence-based medicine, published a statement on the website of their institution, Ontario’s McMaster University, condemning their work’s use in support of age-minimum laws for paediatric gender transition.
Guyatt and his colleagues are the authors of three systematic reviews, evidence-based medicine’s gold standard, finding that “very low” quality evidence underpins the use of puberty blockers, cross-sex hormones, and mastectomy as “treatments” for adolescents in distress about their sexed bodies. This means there is “very low certainty” the purported benefits outweigh the possible risks.
The findings directly challenge the prevailing narrative among American and Canadian medical associations that paediatric medical transition is an evidence-based practice. Yet they are consistent with other systematic reviews on the topic, which have led several European health authorities to greatly restrict minors’ access to the controversial procedures.
In their statement, Guyatt and his colleagues respond to concerns raised by “[m]embers and allies of 2SLGBTQIA+ communities” who believe these interventions should be available for kids who want them, by agreeing that it is “unconscionable” for lawmakers to cite the McMaster reviews as justification for age-minimum laws. Over two dozen such laws have been passed primarily in Republican-held states, and in June the United States Supreme Court upheld them as constitutional.
Guyatt’s own research has found that evidence for these invasive and potentially irreversible interventions is missing. He has stated there are “serious problems” with guidelines put together by American medical associations like the Endocrine Society, and noted these are often based on systematic reviews which did not assess whether such interventions were actually alleviating the symptoms of gender dysphoria. Nevertheless, in their statement, Guyatt and his colleagues call paediatric gender transition “medically necessary.”
Guyatt and his colleagues have gone farther, seeking to pull their names from two additional systematic reviews they have been working on, one dealing with social transition, and the other with breast binding and genital tucking. The move appears geared to weaken the impact of these reviews or even prevent their publication altogether.
“Formerly, I thought my job ended with conducting and reporting high quality research,” Guyatt posted on social media, “I now realize I have an additional responsibility to address how my work is used.”
In accordance with his newfound sense of “additional responsibility,” Guyatt agreed to make a charitable donation to Egale Canada, an LGBT advocacy group. Egale says that puberty blockers are “considered very safe overall,” and they “offer tremendous mental health benefits,” statements that directly contradict Guyatt’s own review on puberty blockers. Asked why he donated, Guyatt said that he was encouraged by “colleagues,” and complied because he is “trans-sympathetic.”
Why is the father of evidence-based medicine joining a campaign against his own field? On the surface, Guyatt and his co-authors cite the principle of patient “autonomy.” They argue that “respect for autonomy becomes particularly important when the certainty of the evidence is low or very low.” Faced with profound uncertainty of whether hormones and surgeries will benefit developing teens, the reasoning goes, doctors should be even more deferential to the “values and preferences” of their patients.
Evidence-based medicine, as defined by Guyatt (who coined the term), emphasises that moving from evidence to recommendations requires taking other factors, including patient “values and preferences,” into account. But Guyatt’s claim about autonomy in this context makes little sense.
First, properly understood, the value of patient autonomy is not a sword for patients to demand treatments, it is a shield against unwanted interventions. Respect for patient autonomy as a guiding value grew out of 20th century experience with coercive human experimentation. Simply put, Guyatt does not explain why “autonomy” (as he frames it) should trump the other cardinal principles of medical ethics, non-maleficence (“first, do no harm”), beneficence, and justice, that doctors have a professional duty to uphold.
Guyatt himself addressed these issues at a conference hosted by the Society for Evidence-Based Gender Medicine (SEGM) in 2023. Asked about clinical decision-making in the context of low-certainty evidence, Guyatt said, “Clinicians never have and never should have the obligation to give interventions that they think are not in the patient’s best interest… I would say your obligation is to make it clear to the patient that you think they are misguided and that their current plan and course of action is actually not in their best interest.”
Second, even if one elevates “autonomy” over the other ethical principles and reduces medicine to consumerism, there remains the fact that the “values and preferences” in question are of young teens. According to another approach, grounded in “the child’s right to an open future,” autonomy for young adolescents entails a “right in trust” to be exercised by competent and informed parents or caregivers for the sake of the child’s future welfare. Deferring to a teen’s “values and preferences” may compromise an open future. There is a reason that society does not allow young teens to buy alcohol, take out a credit card, or get a tattoo or plastic surgery. The latter two examples are undoubtedly expressions of personal autonomy when pursued by adults.
Even Guyatt, who likely places far more weight on patient autonomy than most doctors, has said in the past that autonomy is a sliding scale. At the 2023 SEGM conference, Guyatt said, “Most of us would agree that you’re going to put less value in the children’s autonomy when they’re nine, and you might put more when they’re 14, and you’ll certainly put more when they’re 18.”
Of note, the fact that parents are involved in these decisions does not lower the threshold of justification, but just the opposite, it makes questions of evidence and “best interests” (rather than current patient desires) that much more important.
Can young teens “autonomously” sign away their future fertility or consent to drugs and surgeries that can leave them with sexual dysfunction, bone health problems, cognitive impairment, or higher risk for cancer and cardiovascular disease, when there is no credible evidence of benefit and when the usefulness of a “gender dysphoria” diagnosis is deeply contested?
Guyatt and his colleagues claim it is “unconscionable” for policymakers to prohibit doctors from offering these chemical and surgical interventions. It does not seem to matter that these same doctors have consistently ignored Guyatt’s own systematic reviews, approved kids for medical transition on demand, and written or endorsed guidelines that Guyatt himself has deemed inconsistent with evidence-based medicine.
I would argue that it is unconscionable for policymakers not to prohibit these interventions under these circumstances. At the very least, this is a question on which reasonable people can disagree, and the substance of that disagreement would not be something over which evidence-based medicine experts like Guyatt have any special authority by virtue of their professional background.
The real reason for the Aug. 14 statement by Guyatt and his colleagues, however, was not disagreement over the meaning or importance of autonomy in paediatric medicine.
In a remarkable interview with journalist Jesse Singal, Guyatt admitted that transgender activists had pressured him, his junior colleagues, and McMaster University into renouncing their own work and ceasing any further work that could compromise minors’ access to “gender-affirming care.” A trans activist-run Instagram account has been leading a campaign of harassment against Guyatt and his colleagues, which in some cases resulted in nasty, in-person confrontations.
Guyatt told Singal that the personal and professional repercussions to his colleagues were just too much. “They’re all terrified. They’re all traumatized,” he said. Guyatt explained that although he feels “invulnerable,” his junior colleagues are not, and he felt a duty to protect them.
Guyatt’s intentions vis-à-vis his colleagues may be noble, but his actions demonstrate the missing link connecting the academic field of evidence-based medicine to real-world medical policy. That link is courage.
Evidence-based medicine is of little importance if the field’s biggest names are unwilling to stand up to activist bullying. A petition is now circulating among McMaster faculty and students demanding that Guyatt and his team “pursue retraction” of their own research. It remains to be seen what they will do.
Guyatt’s “fall from grace,” as journalist Ben Ryan put it, is a cautionary tale about capitulation to mobs. Put your professional integrity up for sale, and the question will quickly become how low a bid you will accept.
Dr. Roy Eappen has been a practicing endocrinologist in Montreal since 1990, and he is an assistant professor of Medicine at McGill University. He is a senior fellow at the Macdonald-Laurier Institute and at Do No Harm.
