TORONTO -- Female scientists are less successful than their male counterparts in being awarded research grants from Canada's federal funding agency, a gender gap that often can have long-term consequences for women's careers, a study has found.

The study analyzed almost 24,000 grant applications made to the Canadian Institutes of Health Research (CIHR) between 2011 and 2016, comparing outcomes when reviewers assessing a proposal were required to focus on the principal investigator, rather than the quality of their science.

"We found that when reviewers primarily evaluate the proposed research ... male and female scientists have about an equal shot," lead author Holly Witteman, an associate professor of medicine at Laval University, said from Quebec City.

"However, when reviewers evaluate the scientist, then women don't do as well."

In 2014, CIHR divided funding applications into two new grant schemes, one with an explicit review focus on the applicant and the other on the research proposed, creating what Witteman calls a unique natural experiment that allowed for comparison based on gender.

Overall, about 16 per cent of grant proposals ended up being funded by CIHR. When assessments were done primarily on the quality of the science, the gender gap in success rates between male and female applicants was 0.9 percentage points.

But when the evaluations were done based primarily on the leadership and expertise of the principal investigator, the gender gap was four percentage points, with men faring better than women in obtaining grants for their research.

"Our study offers the first robust evidence showing that gender gaps in research funding stem from evaluations of the scientist, not the science," said Witteman.

"Bias in grant review, whether individual or systemic, prevents the best research from being funded. When this occurs, lines of research go unstudied, careers are damaged, individual rights and potential go unrealized, and funding agencies are unable to deliver the best value for money," she added.

The Canadian study is part of an extensive package of research papers and commentaries, entitled Advancing Women in Science, Medicine and Global Health, published Thursday in the journal The Lancet.

A Lancet editorial reads: "It is well-established that women are underrepresented in positions of power and leadership, undervalued, and experience discrimination and gender-based violence in scientific and health disciplines across the world.... Despite decades of recognition, these problems have proved stubbornly persistent.... Gender equity is not only a matter of justice and rights, it is crucial for producing the best research and providing the best care to patients."

Witteman, who has been a CIHR grant recipient, said a large body of evidence shows that compared with men, women are less likely to be viewed as scientific leaders, contribute more labour for less credit on research publications, and are less often invited as speakers at medical and scientific conferences.

Female faculty are less likely to reach higher ranks in medical schools than male faculty, even after accounting for age, experience, specialty and research productivity, she said. For example, women account for only 16 per cent of medical school deans and 15 per cent of department chairs in Canada and the U.S. -- despite the fact that slightly more women than men are enrolled in medical schools.

"The reason this matters to me," Witteman said of the gender gap in CIHR research grants, "is these are public funds -- we don't have enough of them.

"And when they are allocated in a way that is introducing bias, what that means is we are failing to fund the best research," she said. "And one of the other things that we know is that female scientists are more likely to do work that is more relevant to women's health.

"So it isn't just about the careers of scientists, it's also about what kind of work are we funding and what does that mean for the people of Canada?"

The study's findings are important, said Adrian Mota, associate vice-president of research programs at CIHR. "As the federal funding agency, we want to make sure our programs are free from things like systemic bias."

Mota said CIHR has already begun to institute changes to try to level the playing field between male and female scientists who apply for a piece of the agency's roughly $650 million annual funding pie.

That includes changes to its three-stage Foundation grant program, which is aimed at evaluating proposals from well-established scientists in Canada, based to a large extent on their research track record, the impact of published work and their leadership abilities.

"We equalize the success rate of women at stage 1, so there's a proportionally equal share going to stage 2," said Mota, explaining that if, for instance, 30 per cent of applicants were female, then 30 per cent of those who move onto to stage 2 in the review process would also be female.

"And then stage 2 really looks at the science and then you see that proportional success rate at stage 2 and stage 3."

Mota said the funding success rate is only one part of the issue of disparity faced by female researchers, who tend to ask for grants that are smaller in size and shorter in duration than those sought by their male counterparts. Letters of support submitted with women's grant applications also often use weaker language than those from men.

"So there's a lot that underlies this," he said Thursday from Ottawa. "It's something that's well-known to us and it's something that's one of our top priorities to address going forward.

"We have an equity strategy and gender equity framework, where we're really digging into the data on a number of equity dimensions to understand what the issues are and to apply preventions to correct them."