A new Ontario study of surgery referrals shows that male doctors are disproportionately referring their patients to male surgeons.

The study, conducted by St. Michael’s Hospital in partnership with non-profit research organization ICES, was published on Wednesday in the Journal of the American Medical Association.

The study looked at nearly 40 million Ontario surgery referrals between Jan. 1, 1997 to Dec. 31, 2016.

Researchers found that males comprised 77.5 per cent of all surgeons, but received 87.1 per cent of referrals from male physicians and 79.3 per cent of referrals from female physicians.

According to the study, “physicians exhibit preferences for male surgeons, and those preferences are strongest amongst male physicians,” while female physicians were less influenced by surgeon gender when making their referrals.

The study found female physicians were 1.6 per cent likelier to refer patients to a female surgeon, while male physicians were 32 per cent likelier to refer patients to a male surgeon.

“During my 20 years in practice, I always had the sense it was easier for my male surgical colleagues to get referrals than it was for me, and the patients they were referred were more likely to need surgery,” Dr. Nancy Baxter, senior author of the study, said.

“Our work demonstrates that my observations were not unique, but reflect gender bias that affects the lives and livelihoods of all female surgeons in the province,” Dr. Baxte said.

The study also found that, in turn, female surgeons “have fewer opportunities to perform highly remunerated operations.”

The authors claim that this disparity will not lessen over time as more women enter the surgical field. Instead, they are underlining the need for systemic, focused efforts to reduce the bias on female surgeons.

They recommend the education of physicians on the existence and impact of implicit biases and the adoption of single-entry referral models coupled with frequent auditing.

In March, one of the authors of the study and general surgery resident with the University of Toronto, Dr. Fahima Dossa, told CTV News that implicit gender bias in the surgical field was one of the factors fuelling a surgical backlog during the COVID-19 pandemic in Canada.

She also believes that implicit biases can impact women surgeons’ remuneration.

“Women, first of all, are being discouraged from entering surgery to begin with,” Dossa, who is also a PhD candidate with the school’s Institute of Health Policy, Management and Evaluation, said.

“Even once you make the decision to get into surgery, you are nudged or sometimes very much pushed into certain areas that may not be as remunerative. And I don't think that that's a coincidence.”

To push back against the disparities in the surgical field, Dossa endorses providing an environment where there is transparency around the kind of patients surgeons are being referred to.

With files from CTV News’ Solarina Ho.