Gordon Guyatt, a prominent Canadian physician and researcher, is known for coining the term "evidence-based medicine." He was inducted into the Canadian Medical Hall of Fame in 2016 and is recognized as a leading authority in health-related quality of life research, systematic reviews, and guideline development. His contributions include the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool, which helps assess the quality of evidence in research.

Recently, McMaster University, where Guyatt serves as a professor, published a letter addressing concerns raised by members of the 2SLGBTQIA+ community regarding systematic reviews related to gender-affirming care. The letter, co-signed by Guyatt and four other researchers, acknowledged that "only low certainty evidence exists... regarding the benefits of the gender-affirming care interventions addressed in our systematic reviews." This statement indicates that the researchers' confidence in the effectiveness of these interventions is limited, suggesting that actual medical outcomes may differ significantly from what has been communicated to youth and their families.

The letter was a response to worries that their findings could be misused to justify denying essential care, such as puberty blockers and hormone replacement therapy, to transgender youth. The university did not specify which community members raised these concerns, but the letter seems to address criticism stemming from a letter to the editor in the British Medical Journal. In that letter, a critic accused the journal of promoting anti-gender ideology by publishing research from the Society for Evidence Based Gender Medicine (SEGM), which has faced accusations from the Southern Poverty Law Center of being an anti-LGBTQ+ hate group.

SEGM describes itself as committed to promoting evidence-based care for gender-dysphoric individuals, emphasizing ethical principles and informed consent. Guyatt and his colleagues had previously collaborated with SEGM on systematic reviews but stated in their letter that they have since ended their research agreement with the organization. They noted that when the agreement began in 2021, SEGM appeared to be a legitimate, evidence-based organization.

In light of the concerns raised, Guyatt and his colleagues have decided to cease accepting funding from SEGM. They also made a personal donation to Egale Canada, a group focused on legal and justice work for LGBTQ+ rights, in response to community advocates' recommendations. This decision reflects their commitment to addressing the concerns surrounding their research and its implications for transgender youth.