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Patients have better outcomes in hospitals with higher ratio of female surgical teams


Toronto, ON, May 15, 2024 – Care in hospitals with greater than 35% female anesthesiologist and surgeon teams was associated with a 3% reduction in the odds of postoperative complications in the three months following surgery, according to researchers at ICES, Sunnybrook Research Institute, and the University of Toronto.  

This is one of the first studies to focus on sex diversity of operating room teams, building on past work that has compared the impact of individual surgeon and anesthesiologist characteristics on patient outcomes.  

“We wanted to challenge the binary approach of comparing female and male clinicians and rather highlight the importance of diversity as a team asset or bonus in enhancing quality care,” says lead author Julie Hallet, a scientist with ICES and Sunnybrook Research Institute, and Associate Professor in the Temerty Faculty of Medicine’s department of surgery. 

Published in the British Journal of Surgery, the researchers analyzed population-based healthcare data of 709,899 adult patients undergoing major inpatient surgeries in Ontario, Canada between 2009 and 2019.  

Sex diversity of surgical teams was defined as the percent of female anesthesiologists and surgeons among all anesthesiologists and surgeons working in the hospital each year. The primary outcome was 90-day major morbidity, which was analyzed using a standardized classification scale to identify severe post-surgical complications. 

The findings showed that reaching a critical mass of more than 35% female anesthesiologists and surgeons was linked to lower odds of severe complications. The association between greater sex diversity and reduced post-surgical complications was even greater for patients treated by female anesthesiologists and female surgeons, which aligns with previous studies comparing outcomes of male to female surgeons. 

“These results are the start of an important shift in understanding the way in which diversity contributes to better quality care around the time of surgery,” says Hallet. “Ensuring a critical mass of female anesthesiologists and surgeons in operative teams is crucial to performance. Below a critical mass, female clinicians may withhold their perspectives, such that the benefits of diversity can only be achieved once minimum representation is reached.” 

One limitation of the study is that the data did not include gender as a social construct. It is possible that gender roles, behaviours, and attitudes would have influenced the strength of the association. Further research is also needed to explore diversity based on other sociodemographic variables, including but not limited to race and ethnicity. 

Nevertheless, this study is the first to show a robust association between team sex diversity, better patient outcomes, and higher quality care. 

“We hope that these results will encourage hospitals to intentionally foster sex diversity in operating room teams to reduce poor health outcomes, which, in turn, can improve patient satisfaction and promote sustainability of health systems,” says Gianni R. Lorello, staff anesthesiologist at Toronto Western Hospital, University Health Network, and an Associate Professor with Temerty Medicine’s department of anesthesiology and pain medicine. 

“Ensuring sex-diversity in operative teams will require intentional effort for recruitment and retainment policies for female physicians, structural interventions such as minimum representation on teams, and monitoring and reporting of teams’ composition to build institutional accountability in existing systems,” adds Lorello. 

The study, “The association between anesthesiology-surgery team sex-diversity and major morbidity” was published in the British Journal of Surgery.

Authors: Hallet J, Sutradhar R, Flexman A, McIsaac DI, Carrier FM, Turgeon AF, McCartney C, Chan WC, Coburn N, Eskander A, Jerath A, Perez d’Empaire P, Lorello G. 

Founded in 1827, the University of Toronto has evolved into Canada’s leading institution of learning, discovery and knowledge creation. We are proud to be one of the world’s top research-intensive universities, driven to invent and innovate. Our students have the opportunity to learn from and work with preeminent thought leaders through our multidisciplinary network of teaching and research faculty, alumni and partners. The ideas, innovations and actions of more than 590,000 graduates continue to have a positive impact on the world.  

Sunnybrook Research Institute (SRI) is the research arm of Sunnybrook Health Sciences Centre, an internationally recognized academic health sciences centre fully affiliated with the University of Toronto. With well-established programs in basic and applied sciences which span across three scientific platforms and ten clinical programs, SRI is developing innovations in care for the more than 1.1 million patient visits the hospital provides annually. Recognized as a Centre of Excellence in focused ultrasound, SRI has one of the most comprehensive and successful focused ultrasound research programs in the world, with technical, scientific and clinical experts accelerating progress in the field. Learn more at Sunnybrook.ca/research. 

ICES is an independent, not-for-profit research and analytics institute that uses population-based health information to produce knowledge on a broad range of healthcare issues. ICES leads cutting-edge studies and analyses evaluating healthcare policy, delivery, and population outcomes. Our knowledge is highly regarded in Canada and abroad and is widely used by government, hospitals, planners, and practitioners to make decisions about healthcare delivery and to develop policy. For the latest ICES news, follow us on X, formerly Twitter: @ICESOntario


Gabrielle Giroday
Media and Communications Specialist, Temerty Faculty of Medicine
[email protected]  

Misty Pratt 
Senior Communications Associate, ICES
[email protected] 613-882-7065  

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