Gordon Guyatt is a Canadian researcher and anti-transgender activist. From 2021 to 2024, Guyatt’s research on trans healthcare was funded by anti-transgender hate group Society for Evidence-Based Gender Medicine (SEGM). Guyatt was an invited speaker at a 2023 SEGM event.
Guyatt published SEGM-funded research in The BMJ and associated publications. Guyatt is often cited to support anti-trans FUD propaganda that claims trans healthcare is based on “low quality evidence.” Guyatt’s work is often cited in legislation restricting or banning transgender healthcare.
Guyatt has been critical of guidelines on trans healthcare for minors published by the American Academy of Pediatrics and the World Professional Association of Transgender Health.
Guyatt’s GRADE scale was rejected in a 2023 federal ruling about trans healthcare, because 85% of evidence that guides clinical care, across all areas of medicine, would be classified as âlow-qualityâ under Guyatt’s scale.
A 2022 report funded by SEGM and created by Guyatt colleagues Romina Brignardello-Petersen and Wojtek Wiercioch influenced the development of Florida’s 2022 report on trans healthcare for minors as well as UK’s 2024 Cass Review, both used as pretexts for banning care. Guyatt’s work is cited dozens of times in the 2025 US HHS report created as a pretext for banning gender affirming care for minors.
In 2025, Guyatt and team stopped taking funds from SEGM following criticism and made a contribution to Egale Canada.
Background
Gordon Henry Guyatt was born on November 11, 1953 in Hamilton, Ontario. Guyatt earned a bachelor’s degree from University of Toronto and a medical degree from McMaster University, followed by a master’s degree there.
Guyatt is a leading figure in evidence-based medicine, which focuses on using current best evidence in making medical decisions. As part of that work, In 2000 Guyatt and Holger Jens SchĂŒnemann, developed a hierarchy of evidence called the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Guyatt’s work in promoting evidence-based medicine is widely considered one of the most influential recent developments in medicine.
Guyatt and spouse Maureen Meade have three children.
Collaboration with SEGM
In 2021, hate group Society for Evidence-Based Gender Medicine (SEGM) and McMaster University entered into an agreement in which SEGM funded several papers for use in banning trans healthcare for minors.
Guyatt’s MacMaster collaborators:
- Romina Brignardello-Petersen
- Rachel Couban
- Sara Ibrahim
- Chan Kulatunga-Moruzi
- Anna Miroshnychenko
- Steven Montante
- Yetiani RoldĂĄn-Benitez
- Wojtek Wiercioch
- Ray Zhang
2022 Florida report
Florida has long been one of the most hostile US states regarding the rights of trans and gender diverse people. Using slogans like “working together to protect our children” and “let kids be kids,” the state undertook an effort to ban trans healthcare for minors.
The Secretary of the Florida Agency for Health Care Administration (AHCA) requested that Florida’s Medicaid program review “whether treatments are consistent with widely accepted professional medical standards.”
On April 20, 2022, the Florida Department of Health issued a guidance which were used as a pretext for banning coverage of trans healthcare.
The 2022 Florida Department of Health report included five commissioned reports. The authors are all prominent anti-transgender activists:
- Guyatt colleagues Romina Brignardello-Petersen and Wojtek Wiercioch: AHCA Brignardello-Petersen Report
- James Cantor: AHCA Cantor Report
- Quentin Van Meter: AHCA Van Meter Report
- Patrick Lappert: AHCA Lappert report
- G. Kevin Donovan: AHCA Donovan report
The June 2, 2022 AHCA report found that “several services for the treatment of gender dysphoria â i.e., sex reassignment surgery, cross-sex hormones, and puberty blockers â are not consistent with widely accepted professional medical standards and are experimental and investigational with the potential for harmful long term affects.”
On July 8, 2022, Yale University pediatrician Meredithe McNamara and colleagues released “A Critical Review of the June 2022 Florida Medicaid Report on the Medical Treatment of Gender Dysphoria.” In it, they discuss the undisclosed conflict of interest:
The linchpin of the June 2 Report is the analysis by Brignardello-Petersen and Wiercioch (the âBPW documentâ), provided as Attachment C, which purports to be a comprehensive review of the scientific literature on medical treatment for gender dysphoria but, in fact, is extremely narrow in scope and so flawed in its analysis that it merits no scientific weight.
Romina Brignardello-Petersen is one of two authors of the document provided as Attachment C to the June 2 Report. Although Brignardello-Petersen claims to have no research interests in medical care for transgender youth,25 she has conducted research for the Society for Evidence-Based Gender Medicine (âSEGMâ). 26 Although SEGM claims to be an international medical society, it is actually an activist group that opposes standard medical care for gender dysphoria. The SEGM has no publications or conferences and seems to consist solely of a website created by a small group of people with limited or no scientific credentials or clinical experience. The site presents a cherry-picked collection of studies and narrative content that is full of scientific errors. 27
26. Like the van Meter and Cantor attachments, the BPW document provides no express statement of conflicts of interest. The BPW document does offer a statement of âcredentials and expertise,â in which she declares that âher research interests are not in this area,â meaning apparently research on medical care for gender dysphoria.
27. For one example of the purported research that Brignardello-Petersen apparently assisted in, see Alison Clayton et al., Commentary: the Signal and the Noise â Questioning the Benefits of Puberty Blockers for Youth with Gender Dysphoria â A Commentary on Rew et al. (2021), Child and Adolescent Mental Health, Dec. 22, 2021, at https://acamh.onlinelibrary.wiley.com/doi/10.1111/camh.12533. In the âAcknowledgementsâ section, the authors state, âWe would also like to thank the Society for Evidence-based Gender Medicine (SEGM) for providing access to several experts who helped shape this commentary and ensure its accuracy. Specifically, we would like to thank Dr. Romina Brignardello Petersen [sic] for contributing her methodological expertise.â
2023 SEGM conference
In 2023, SEGM held a conference in New York City. Guyatt was a featured speaker along with Romina Brignardello-Petersen, Ivan D. Florez, and Dena Zeraatkar. According to anti-trans activist Frieda Klotz:
Among those present at SEGMâs New York conference was Gordon Guyatt, a professor at McMaster University in Canada, and a founding figure in evidence-based medicine, a movement that seeks to bring well-designed research into clinical decision-making. Guyatt is among the experts developing systematic reviews sponsored by SEGM on topics including chest-binding and genital tucking, and puberty blockers and cross-sex hormones for people 25 and under.
Guyatt had already voiced concerns about the science underpinning gender-affirming care. When the AAP announced in August 2023 that it would reaffirm its 2018 policy and develop updated guidelines based on its own systematic review of the evidence, Guyatt told The New York Times the organization had put âthe cart before the horse.â After he attended the SEGM conference, some of his colleagues warned him that his involvement in the contentious debate could damage his reputation.
During his presentation, Guyatt addressed a key question for gender medicine: Can randomized controlled trials be used to test treatments? RCTs are viewed by most gender-affirming researchers as unethical in teen patients, on the grounds that study participants in the control group would be deprived of beneficial care. Others have said that an RCT would be impractically difficult.
According to an article in UnHerd by anti-trans activist Benjamin Ryan:
In 2023, when Guyatt sat on a panel at SEGMâs conference in New York, he sounded a different note. Asked whether it was acceptable to call pediatric gender medicine âlife-savingâ and âmedically necessaryâ when itâs backed only by low-quality evidence, he said: âOf course not.â The rational approach, he said, would be ânot to say itâs medically necessary, itâs to say we are putting an extremely high value on autonomy.â Indeed, the recent statement from Guyattâs team asserted that when a treatment is backed by low or very low certainty evidence then the âhigh respect for autonomy becomes particularly important.â
“Low-quality evidence”
In sharing a report in The BMJ by anti-trans activist Jennifer Block, Guyatt stated “Current American guidelines for managing gender dysphoria in adolescents untrustworthy.”
Christina Jewett and Megan Twohey also parroted the âlow-quality evidenceâ claim put forth by anti-trans activists, based on Guyatt’s scale. Federal judge Sarah E. Geraghty rejected these claims in a 2023 Georgia case where anti-trans activists Paul Hruz, Michael Laidlaw, and James Cantor testified against Yale University professor of pediatrics Meredithe McNamara:
The undisputed record shows that clinical medical decision-making, including in pediatric or adolescent medicine, often is not guided by evidence that would qualify as âhigh qualityâ on the scales used by Defendantsâ experts. 30 (Doc. 70-1, McNamara Decl. ¶¶ 23â28; Tr. 74:11â75:1 (McNamara Testimony); Tr. 133:614 (Hruz Testimony).) In fact, the record shows that less than 15 percent of medical treatments are supported by âhigh-quality evidence,â or in other words that 85 percent of evidence that guides clinical care, across all areas of medicine, would be classified as âlow-qualityâ under the scale used by Defendantsâ experts. (Doc. 70-1, McNamara Decl. ¶ 25; Tr. 74:11â75:1.) Defendants do not refute Dr. McNamaraâs testimony on this point, and indeed they âconcedeâ that âlow-qualityâ evidence âcan be considered.â 31 [emphasis mine]
Geraghty also noted the obvious biases of Hruz, Laidlaw and Cantor:
Defendantsâ expertsâ insistence on a very high threshold of evidence in the context of claims about hormone therapyâs safety and benefits, and on the other hand their tolerance of a much lower threshold of evidence for claims about its risks, the likelihood of desistance and/or regret, and their notions about the ideological bias of a medical establishment that largely disagrees with them. That is cause for some concern about the weight to be assigned to their views, although the Court does not doubt that those they express are genuinely held.
(âDr. [Paul] Hruz fended and parried questions and generally testified as a deeply biased advocate, not as an expert sharing relevant evidence-based information and opinions. I do not credit his testimony.â); Eknes-Tucker v. Marshall, 603 F. Supp. 3d 1131, 1142â43 (M.D. Ala. 2022) (explaining that the court gave Dr. James Cantorâs âtestimony regarding the treatment of gender dysphoria in minors very little weightâ); C. P. by & through Pritchard v. Blue Cross Blue Shield of Illinois, No. 3:20-CV-06145-RJB, 2022 WL 17092846, at *4 (W.D. Wash. Nov. 21, 2022) (noting that it was a âclose questionâ as to whether Dr. Michael Laidlaw was qualified to testify about the medical necessity of gender-affirming care because he has treated only two patients with gender dysphoria and has done no original research on gender identity).
2025 mastectomy paper
Anna Miroshnychenko is lead author of an evidence review funded by hate group Society for Evidence-Based Gender Medicine (SEGM). According to PROSPERO:
Co-authors:
- Romina Brignardello-Petersen
- Rachel Couban
- Sara Ibrahim
- Chan Kulatunga-Moruzi
- Gordon Guyatt
- Steven Montante
- Yetiani RoldĂĄn-Benitez
Collaborators listed are key figures in global anti-trans activism:
- Dr Alison Clayton, University of Melbourne
- Dr Patrick Hunter, University of Central Florida College of Medicine
- Dr William Malone, Idaho College of Osteopathic Medicine
- Dr Lori Regenstreif, McMaster University
- Dr Kristen Dahlin, Dialectical Behavior Therapy Center of San Diego
- Dr Julia Mason, Calcagno Pediatrics
- Dr Lisa Littman, The Institute for Comprehensive Gender Dysphoria Research
- Dr Rebecca Shiner, Colgate University
- Dr Chan Moruzi, Independent researcher
- E. Abbruzzese, Society for Evidence-based Gender Medicine
- Dr Steven Montante, Montante Plastic Surgery & Aesthetics
“Funding: This systematic review is part of a large research project funded through a research agreement between the Society for Evidence-based Gender Medicine (SEGM), the sponsor, and McMaster.”
Coverage in anti-trans media
Anti-trans activists who promoted Guyatt prior to the 2024 statement include SEGM founder William Malone, as well as:
- Jennifer Block
- “Christina Buttons”
- James Cantor
- Alison Clayton
- Nicholas Confessore
- Azeen Ghorayshi
- Paul Hruz
- Mia Hughes
- Christina Jewett
- Sharon Kirkey
- Michael Laidlaw
- Helen Lewis
- Bernard Lane
- Benjamin Ryan
- Leor Sapir
- Jesse Singal
- Price St. Clair
- Megan Twohey
- The Economist editors
- Our Duty
- SEGM
Anti-trans extremist Jesse Singal was especially offended by this site’s profile of Guyatt, writing in UnHerd:
James has targeted a number of other responsible and careful clinicians in the field of youth gender medicine. She has also created a page for Gordon Guyatt, a legend within the field of medical research. He is one of the founders of evidence-based medicine, a (genuinely) lifesaving movement to improve the quality of medical research. Because Guyatt spoke at SEGM, heâs now a transphobe, according to the unerring moral judgment of Andrea James. He is tarred as an âanti-transgender activistâ â ironic, given that when I asked him about the claim that questioning the evidence for transgender medicine is itself transphobic, he replied: âYouâre doing harm to transgender people if you donât question the evidence.â
2025 statement
In 2025, student activists at McMaster University began a campaign to get Guyatt to acknowledge that the SEGM-McMaster research partnership “utilized GRADE to lend credibility to pseudoscience that opposes gender affirming care.” In June, members confronted Guyatt and Brignardello-Petersen, who both quickly left without commenting.
According to an interview in the National Post, Guyatt was âholding a workshop at McMaster and the people showed up, took videos of us coming in and confronted us. Then they had to be asked to leave and then subsequently (they) posted things on the internet, as well as writing letters to the university.â Guyatt described these tactics as “rather obnoxious.” Guyatt added, âThe university, as far as I can tell, is very nervous about its image around this whole thing, and the PR people within the university are very uncomfortable with being put in this position. The general PR stance is, âBe quiet. Donât say anything. Anything you say will get into more trouble. Just be quiet. Itâll blow over.â Thatâs the general PR stance. […] I was not as vividly aware as to what an extreme political environment it is.â
In August 2025, after Guyatt’s work had been cited extensively as a pretext to ban trans healthcare for minors, Guyatt stated, “Formerly, I thought my job ended with conducting and reporting high quality research. I now realize I have an additional responsibility to address how my work is used.”
Guyatt and team released a statement. Several people involved did not sign it, most notably Anna Miroshnychenko and Chan Kulatunga-Moruzi. It stated in part:
Members and allies of 2SLGBTQIA+ communities have raised concerns about recent systematic reviews related to gender-affirming care. These concerns center on the funding source, and specifically on the potential for the research to be misused to harm trans youth and to deny gender-affirming care. […]
In contrast to the way findings and presentation of our systematic reviews have been misrepresented and misinterpreted, they in fact show that, like the majority of what we do as physicians, the outcomes of specific aspects of care for transgender patients remain uncertain. The appropriate response to such uncertainty is shared decision-making that fully respects the autonomy of the individuals involved. Therefore, we have prepared the following letter related to our SEGM-sponsored systematic reviews:
It is profoundly misguided to cast health care based on low-certainty evidence as bad care or as care driven by ideology, and low-certainty evidence as bad science. Many of the interventions we offer are based on low certainty evidence, and enlightened individuals often legitimately and wisely choose such interventions. Thus, forbidding delivery of gender-affirming care and limiting medical management options on the basis of low certainty evidence is a clear violation of the principles of evidence-based shared decision-making and is unconscionable. The appropriate use of our work is in ensuring patients receive needed care and in helping TGD patients and their clinicians in decision making.âŻ
We acknowledge concerns that have been raised.1 Our research agreement with SEGM ended in 2024. When the agreement started in 2021, the organization appeared to us as non-trans, cis-gender researchers to be legitimately evidence-based.
We will no longer accept funding from SEGM. As recommended by community advocates, we have also personally made a donation to Egale Canadaâs legal and justice work, noting their litigation efforts aimed at preventing the denial of medically necessary care for gender-diverse youth.
- Gordon Guyatt, MD, MSc
- Romina Brignardello-Petersen, DDS, MSc, PhD
- Sara Ibrahim, BHSc, PhD student
- Yetiani RoldĂĄn-Benitez, MD, MSc
- Rachel Couban, MA, MISt
Response by anti-trans activists
Following the release of this statement, Guyatt was criticized by many of the anti-trans activists who had been misusing and misrepresenting Guyatt’s SEGM-funded reports, inlcuding:
- “Michelle Alleva” posted on X: “If a doctor offers a treatment that is essentially pseudoscience, can they claim to be practising “evidence based medicine” simply by prioritizing patient autonomy?”
- Oren Amitay posted on X: “@jessesingal’s interview w/ @GuyattGH makes it clear he bent the knee simply out of fear his colleagues would be further “traumatized” by extremely aggressive, “unhinged,” self-serving, unprincipled, (malignantly) narcissistic (not a dx), ideologically driven &/or dangerous TRAs.”
- J. Michael Bailey posted on X: “Guyatt is not intellectually brave, apparently.”
- “Billy Bragg” posted on X: “Face your conscience, causing more harm won’t save you.”
- “Christina Buttons” posted on X: “If you go down this route, you canât call yourself a serious scientist anymore, because youâll have become an activist, and the two are mutually exclusive.”
- Corinna Cohn posted on X: “If the renowned Gordon Guyatt can be driven to public contrition, then anyone can be quieted.”
- “Justine Deterling” posted on X: “Trans activism destroys the credibility of everything it touches, including your reputation.”
- Joe Duarte posted on X: “You’re destroying your legacy for a political ideology, in fact the worst political ideology of all time.”
- Roy Eappen posted on X: “Iâm very disappointing that you seem to have abandoned this work to satisfy activists who will never be satisfied. Autonomy is only one aspect as you well know. What about Harms. Should we go back to lobotomies because patents have unruly children?”
- Joseph Figliolia posted in City Journal: “McMaster University Fails the Bioethics Test”
- Stanley Goldfarb posted on X: “Guyatt and McMaster took years to build a sterling reputation and threw it away in one astonishing interview”
- Glenna Goldis posted several times on X: @GuyattGH, pillar of the medical community, tried to bully @segm_ebm into fighting for pediatric gender medicine. […] I see no evidence of niceness. He’s just throwing punches on behalf of his tribe, doctors
- Eithan Haim posted on Substack: “Autonomy Does Not Trump Evidence: A Response to Dr. Gordon Guyatt”
- J.D. Haltigan posted on X: “Does this surprise you? Did you think he would not sell out?”
- Amy Hamm posted in National Post: “Father of ‘evidence-based medicine’ turns his back on science.”
- Bev Jackson posted on X: “I feel a sense of vicarious embarrassment for you.”
- Helen Joyce posted several times on X: “To watch someone torch their reputation in real time is painful. And the drive-by on Zhenya – all I can say is she will come out of this a sight better than GG when all is said and done. […] Gordon Guyatt flushing his life’s work down the pan is one of the most depressing self-beclownings I’ve seen yet in the gender wars.”
- Jonathan Kay posted in Quillette: “Guyatt and his colleagues published their grovelling confession and repentance.”
- Bernard Lane posted on Substack: “Activist-biased medicine?”
- LGB AllianceLGB Alliance vs. transgender people Canada wrote an open letter https://www.lgballiance.ca/news/letter-to-the-faculty-of-health-sciences-mcmaster-university
- Julia Mason posted on X: “You could also ask him to stop slandering SEGM.”
- Travis Morrell posted on X: “Blink three times fast if âcommunity advocatesâ have kidnapped you and are writing checks to TQ+ activist funds on your behalf.”
- Prisha Mosley posted on X: “What about your responsibility to the desperate and vulnerable people?”
- Matt Osborn posted on X: “Why are you so eager to chop bits off gay kids to make them look straight? Explain”
- Simon Amaya Price posted on X: “No apology will be enough for the trans activists. They will always hate you.”
- Our Duty Canada posted on their site: “Founder of Evidence-Based Medicine Concedes to Trans-Activist Pressure”
- Jamie Reed posted on X: “Legislators have not misused these reviews. […] We use every tool that we have in order to stop this tragedy.”
- Benjamin Ryan posted in UnHerd “Gordon Guyatt, an authority on medical research, capitulated to a transgender activist mob and undermined his own field in the process.”
- Jesse Singal posted twice on Substack: “The Disaster at McMaster”
- Themis Resource Fund posted on X: :The only unconscionable use of evidence based medicine is by Gordon Guyatt himself.”
- Women’s Declaration International Quebec posted on X: “Blink your eyes in Morse code if you need help Dr @GuyattGH !”
- Colin Wright posted on X: “@brad_polumbo and I cover a shocking development from the father of modern evidence-based medicine himself, Dr. Gordon Guyatt, who has seemingly abandoned the very principles he pioneered.”
In an interview with the National Post, Guyatt said: “I was not as vividly aware as to what an extreme political environment it is.”
In an interview with SEGM’s embedded reporter Jesse Singal, who was clearly taken aback by this development, Guyatt said, “My opinion is SEGM has no respect for autonomy, that they take the position that we should ban the procedures, that patients should not be able to access them, and I have big problems with that.” Guyatt added, “I indeed did not have conscious awareness of a formal agreement between McMaster and SEGM until the controversy.” Guyatt reportedly cut ties with SEGM’s Zhenya Abbruzzese, saying, “I canât think of before where there was a problem where somehow my work was misused in a nefarious and unconscionable way.”
References
M-K, Gideon (September 1, 2025). A Fight Over Evidence-Based Medicine And Gender Affirming Care. Health Nerd https://gidmk.substack.com/p/a-fight-over-evidence-based-medicine
Boothe, Katherine; skaidra, sasha; Jones, Angela; Johnson, Jessica (July 12, 2025). Opinion | No pride in pseudo-science. The Hamilton Spectator https://www.thespec.com/opinion/contributors/no-pride-in-pseudo-science/article_095f09f0-5a70-528b-826c-07edd4811f6d.html
Carnell, Henry; Pauly, Madison (May 1, 2025). âAn Anti-Trans Fever Dreamâ: HHS Publishes Attack on Gender-Affirming Youth Care. Mother Jones https://www.motherjones.com/politics/2025/05/hhs-trans-youth-gender-care-report/
White, Margaret (February 9, 2025). The BMJ needs to take responsibility for its own part in enabling anti-gender ideology. The BMJ https://www.bmj.com/content/388/bmj.r253/rr-0
Cohen, Deborah (December 8, 2024). Puberty blockers: Can a drug trial solve one of medicine’s most controversial debates? BBC https://www.bbc.com/news/articles/clyd2qe5kkjo
Jones, Zinnia (November 29, 2023). New trial exhibits in Doe v. Ladapo: DOH worked with Genspect leaders Stella OâMalley and Joe Burgo in July 2022; Hilary Cass met SEGMâs Patrick Hunter to discuss Floridaâs anti-trans report; Jamie Reedâs attorney Vernadette Broyles chose the lineup of detransitioners speaking at the Board of Medicine. Gender Analysis https://genderanalysis.net/2023/11/new-trial-exhibits-in-doe-v-ladapo-doh-worked-with-genspect-leaders-stella-omalley-and-joe-burgo-in-july-2022-hilary-cass-met-segms-patrick-hunter-to-discuss-floridas-ant/
Jones, Zinnia (October 1, 2023). SEGM conference flier revealed: Invited speakers and schedule for October 9-12 New York City conference of the anti-trans Society for Evidence-based Gender Medicine. Gender Analysis https://genderanalysis.net/2023/10/segm-conference-flier-revealed-invited-speakers-and-schedule-for-october-9-12-new-york-city-conference-of-the-anti-trans-society-for-evidence-based-medicine/
Coverage in anti-trans press
Ryan, Benjamin (September 3, 2025). The taming of a gender researcher: Activists targeted Gordon Guyattâs promising field. UnHerd https://unherd.com/2025/09/the-taming-of-a-gender-researcher/
Kay, Jonathan (September 3, 2025). An Uproar Over Facts. Quillette https://quillette.com/2025/09/03/an-uproar-over-facts-mcmaster-gender-trans-health/
Figliola, Joseph (August 29, 2025). McMaster University Fails the Bioethics Test. City Journal https://www.city-journal.org/article/mcmaster-university-gender-medicine-research
Singal, Jesse (August 27, 2025). The Disaster At McMaster Part 2: My Interview With Gordon Guyatt. Singal-Minded https://jessesingal.substack.com/p/the-disaster-at-mcmaster-part-2-my
Singal, Jesse (August 27, 2025). The Disaster At McMaster, Part 1. Singal-Minded https://jessesingal.substack.com/p/the-disaster-at-mcmaster-part-1
Higgins, Michael (August 26, 2025). Michael Higgins: ‘Naive’ Canadian doctor embroiled in trans controversy. National Post https://nationalpost.com/opinion/naive-canadian-doctor-embroiled-in-trans-controversy
Hamm, Amy (August 24, 2025). Amy Hamm: Father of ‘evidence-based medicine’ turns his back on science. National Post https://nationalpost.com/opinion/father-of-evidence-based-medicine-turns-his-back-on-science
Bennet, Melanie (Aug 22, 2025). Canadian doctors who found weak case for ‘gender intervention’ bow to activists. Juno News https://www.junonews.com/p/canadian-doctors-who-found-weak-case
Haim, Eithan (August 21, 2025). Autonomy Does Not Trump Evidence: A Response to Dr. Gordon Guyatt. Reality’s Last Stand https://www.realityslaststand.com/p/autonomy-does-not-trump-evidence
[Singal, Jesse] (Apr 30, 2025). A landmark study of gender medicine is caught in an ethics row. The Economist https://www.economist.com/science-and-technology/2025/04/30/a-landmark-study-of-gender-medicine-is-caught-in-an-ethics-row
Clayton, A. (2025). Gender-affirming hormone treatment for young people with gender dysphoria: where do we go from here? Archives of Disease in Childhood, 110(6), 415â416. https://doi.org/10.1136/archdischild-2025-328478
Les, J. Edward (March 6, 2025). The Strange Construct of Gender Ideology Takes Another Hit. Epoch Times https://www.theepochtimes.com/opinion/the-strange-construct-of-gender-ideology-takes-another-hit-5817937
Staff report (February 28, 2025). New Study Finds Evidence on Puberty Blockers Is Uncertain. Psychreg https://www.psychreg.org/new-study-finds-evidence-puberty-blockers-uncertain/
Alencar, Hadassah (February 12, 2925). Two Canadian reviews find insufficient evidence for gender-affirming care. Canadian Affairs https://www.canadianaffairs.news/2025/02/12/two-canadian-reviews-find-insufficient-evidence-for-gender-affirming-care/
Our Duty (February 10, 2025). Two Canadian Reviews Echo the Cass Review- No Evidence for Pushing Puberty Blockers and Synthetic Sex Hormones. https://ourduty.group/2025/02/10/two-canadian-reviews-echo-the-cass-review-no-evidence-for-pushing-puberty-blockers-and-synthetic-sex-hormones/
Hughes, Mia (February 5, 2025). The evidence is in, again. Puberty suppression for adolescents is still a bad idea: Mia Hughes for Inside Policy. Macdonald-Laurier Institute https://macdonaldlaurier.ca/the-evidence-is-in-again-puberty-suppression-for-adolescents-is-still-a-bad-idea-mia-hughes-for-inside-policy/
Ryan, Benjamin (January 23, 2025). New Research Raises More Doubts About Safety and Benefits of Gender Transition Treatments for Minors. New York Sun https://www.nysun.com/article/new-research-raises-more-doubts-about-safety-and-benefits-of-gender-transition-treatments-for-minors
Block, Jennifer (October 30, 2024). Dispute arises over World Professional Association for Transgender Healthâs involvement in WHOâs trans health guideline. The BMJ https://www.bmj.com/content/387/bmj.q2227
Singal, Jesse (August 19, 2024). Yaleâs âIntegrity Projectâ Is Spreading Misinformation About The Cass Review And Youth Gender Medicine. Singal-Minded https://jessesingal.substack.com/p/yales-integrity-project-is-spreading
Klotz, Frieda (May 20, 2024). Pediatric Transgender Care and the Contentious Rise of SEGM. Undark https://undark.org/2024/05/20/pediatric-transgender-care-contentious-segm/
Confessore, Nicholas (June 19, 2025). How the Transgender Rights Movement Bet on the Supreme Court and Lost. New York Times https://www.nytimes.com/2025/06/19/magazine/scotus-transgender-care-tennessee-skrmetti.html
Gorin, Moti (June 6, 2024). What Is the Aim of Pediatric âGender-Affirmingâ Care? Hastings Center Report, 54(3), 35â50. https://doi.org/10.1002/hast.1583
Sapir, Leor (May 8, 2024). What Does Quality of Evidence Mean? Gender clinician Jack Turban misunderstands key concepts in evidence-based medicine. City Journal https://www.city-journal.org/article/what-does-quality-of-evidence-mean
Lewis, Helen (May 4, 2023). The Only Way Out of the Child-Gender Culture War. The Atlantic https://www.theatlantic.com/ideas/archive/2023/05/texas-puberty-blockers-gender-care-transgender-rights/673941/
Singal, Jesse (April 18, 2023). The media is spreading bad trans science. Misleading studies are being taken as gospel. UnHerd https://unherd.com/2023/04/the-media-is-spreading-bad-trans-science/
SEGM (April 14, 2023). The Evidence to Support Medicalised Gender Transitions in Adolescents is Worryingly Weak. https://segm.org/The-Economist-evidence-for-gender-transitions-in-adolescence-worryingly-weak
Block, Jennifer (August 14, 2023). US paediatric leaders back gender affirming approach while also ordering evidence review. The BMJ https://www.bmj.com/content/382/bmj.p1877
Ghorayshi, Azeen (August 3, 2023). Medical Group Backs Youth Gender Treatments, but Calls for Research Review. New York Times https://www.nytimes.com/2023/08/03/health/aap-gender-affirming-care-evidence-review.html
Lane, Bernard (March 2, 2023). ‘Untrusty’ guide: Gender-affirming guideline ‘fails’ to make the grade. Gender Clinic News https://www.genderclinicnews.com/p/untrusty-guide
Lane, Bernard (February 23, 2023). Which way to go? Confident treatment advice versus weak evidence. Gender Clinic News https://www.genderclinicnews.com/p/which-way-to-go
Selected publications by Guyatt
Guyatt, Gordon; Brignardello-Petersen, Romina; Ibrahim, Sara; RoldĂĄn-Benitez, Yetiani; Couban, Rachel (August 14, 2025). Systematic reviews related to gender-affirming care. McMaster University https://hei.healthsci.mcmaster.ca/systematic-reviews-related-to-gender-affirming-care/
Miroshnychenko, A., Roldan, Y., Ibrahim, S., Kulatunga-Moruzi, C., Montante, S., Couban, R., Guyatt, G., & Brignardello-Petersen, R. (2025). Puberty blockers for gender dysphoria in youth: A systematic review and meta-analysis. Archives of Disease in Childhood, 110(6), 429â436. https://doi.org/10.1136/archdischild-2024-327909
Miroshnychenko, A., Roldan, Y. M., Ibrahim, S., Kulatunga-Moruzi, C., Dahlin, K., Montante, S., Couban, R., Guyatt, G., & Brignardello-Petersen, R. (2024). Mastectomy for Individuals with Gender Dysphoria Younger Than 26 Years: A Systematic Review and Meta-Analysis. Plastic & Reconstructive Surgery, 155(6), 915â923. https://doi.org/10.1097/prs.0000000000011734
Miroshnychenko, A., Ibrahim, S., Roldan, Y., Kulatunga-Moruzi, C., Montante, S., Couban, R., Guyatt, G., & Brignardello-Petersen, R. (2025). Gender affirming hormone therapy for individuals with gender dysphoria aged less than 26 years: a systematic review and meta-analysis. Archives of Disease in Childhood, 110(6), 437â445. https://doi.org/10.1136/archdischild-2024-327921
Brignardello-Petersen, Romina; Wiercioch, Wojtek (May 16, 2022). Effects of Gender Affirming Therapies in People with Gender Dysphoria: Evaluation of the Best Available Evidence. https://ahca.myflorida.com/content/download/4864/file/AHCA_GAPMS_June_2022_Attachment_C.pdf
Guyatt, G. H., Oxman, A. D., Vist, G. E., Kunz, R., Falck-Ytter, Y., Alonso-Coello, P., & SchĂŒnemann, H. J. (2008). GRADE: an emerging consensus on rating quality of evidence and strength of recommendations. BMJ, 336(7650), 924â926. https://doi.org/10.1136/bmj.39489.470347.ad
Guyatt, G. (1992). Evidence-Based Medicine. A new approach to teaching the practice of medicine. JAMA, 268(17), 2420. https://doi.org/10.1001/jama.1992.03490170092032
Resources
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- Gordon Guyatt
- experts.mcmaster.ca/display/guyatt
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- segm_x_mcmaster: Fighting McMaster Uâs partnership with SEGM