A new study suggests that people undergoing certain surgeries may be safer at hospitals where women make up at least one-third of their surgical team — adding to an already growing pool of research suggesting female doctors may have better patient outcomes than their male peers.

The latest study, published Wednesday in the British Journal of Surgery, looked specifically at the relationship between gender diversity in hospital settings and the incidence of serious post-operative health complications, including death, in Canadian surgical patients during their first three months of recovery. 

Researchers reviewed 709,899 cases between 2009 and 2019 where people had undergone non-emergency but major inpatient procedures at 88 different hospitals. Overall, they found that morbidity — which is generally defined in medical terms as any problem arising from a procedure or treatment — happened in 14.4% of those patients over the 90-day period immediately following surgery. 

The likelihood of dying or suffering major post-op complications in that window was significantly lower in hospitals with women composing more than 35% of the surgeons and anesthetists on staff. According to the study, the odds of major morbidity dropped by 3% for patients in those settings compared with hospitals that had fewer women in those roles. 

In general, the median number of women surgeons and anesthetists on hospital staffs did not quite reach the threshold researchers determined was optimal for patients' success, at just 28% per hospital per year.

That the odds of serious post-op complications or death in the months after surgery were lessened, especially for patients who underwent procedures with a woman surgeon or woman anesthetist as their direct provider, is something the researchers underscored as particularly significant.

"These findings are important for optimizing patient outcomes and quality care by building intentionally diverse teams," they wrote.

This study is not alone in its findings. Last year, another study published in the journal JAMA Surgery found that patients who underwent emergency or elective operations between 2007 and 2019 were less likely to die, be hospitalized again or suffer major health complications within a year of the procedure if they were treated by a woman surgeon. That study examined more than 1 million cases and its results were consistent regardless of individual patients' characteristics, what kind of surgical procedure they had, who their anesthetist was or which hospital they were at during the surgery.

Researchers have for years been trying to unpack the apparent pattern. One group from Harvard's T.H. Chan School of Public Health conducted a study between 2011 and 2014 that aimed to address the question of whether treatments by women physicians were more effective for patients' health. 

The Harvard study looked at more than 1 million patients, all Medicaid beneficiaries who were hospitalized for strokes, heart attacks and other fairly common conditions, for which they all received treatment by general internists. Patients who received care from a female physician were at a 4% lower risk of dying within 30 days, and a 5% lower risk of hospital readmission in the same period, compared with patients who received their care from male physicians.

Dr. Ashish Jha, now the dean of Brown University's School of Public Health and formerly a professor of health policy and director of the Harvard Global Health Institute, told CBS News when that study was published in 2016 that its results signaled a need for additional research to figure out what women physicians are doing to improve their patients' outcomes. He said the study's authors, all of whom are men, were "interested in finding out better why these differences exist, but we don't know why yet." 

In:
• Canada

Emily Mae Czachor

Emily Mae Czachor is a reporter and news editor at CBSNews.com. She covers breaking news, often focusing on crime and extreme weather. Emily Mae has previously written for outlets including the Los Angeles Times, BuzzFeed and Newsweek.

Twitter Instagram