Have you ever tried to solve a puzzle with missing pieces? Now imagine solving it with half the pieces missing. This is what it’s like to do research without considering the effects of sex.
Before thinking about the role that biological sex plays in health, it is important to understand some of the recent history behind research.
For years, women were excluded from participating in clinical trials. In many cases, white males were studied as the “norm” population and it was assumed that people outside this category would have the same response as this group.
Women, it was said, were too difficult to include in clinical trials because of the variation introduced by fluctuating hormone levels, among other reasons. While it is true that hormonal variation can affect some results, funders and regulators recognized in the 1980s and 90s that women needed to be equally included in clinical trials.
Estimates are mixed about whether or not the goal of equal participation in clinical research has been met, but many governments have now mandated the need to include analyses of sex and gender in all research projects. For example, CIHR now requires all funding applicants to integrate these concepts into their research designs, when appropriate.
But this goes beyond the need for inclusion of women in research or consideration of sex and gender in design and analysis. Many of the medical conventions that we rely on are based on research done with only male participants.
A stark example is the diagnosis and treatment of heart attack. Women present with different symptoms than men when they are having a heart attack, but the way heart attack is currently diagnosed is based off of male data.
When someone comes to the emergency department with signs of a heart attack, medical teams use a blood test that measures cardiac troponin, a protein that is released into the blood by the heart muscle during a cardiac event. However, the threshold for this test is based off men.
In fact, healthy women produce about half as much cardiac troponin as men and many women who have had a heart attack show values below the diagnostic threshold of the blood test. This, along with the differences in symptoms, has meant that women have historically been underdiagnosed when it comes to heart attack, which can have serious implications for treatment and overall health.
The many examples of this type of bias points to the need to not only do better going forward, but to seek out research questions based specifically on women.
At CHÉOS, there are many past and ongoing projects that aim to improve our understanding of topics that matter to women.
The CODE-MI Study, led by CHÉOS Scientist Dr. Karin Humphries, is addressing the diagnostic issue in heart attack by testing sex-specific thresholds for the cardiac troponin blood test, rather than one standard threshold.
As part of the FRAILTY-AVR Study, Dr. Sandra Lauck looked at the different factors that affect outcomes following transcatheter aortic valve replacement in older men and women. The study team found that women have greater baseline frailty before the procedure, meaning they have greater complication rates and rehabilitation needs.
These are just a few examples of CHÉOS research that focuses on women-specific topics. Important to note is that this article has not addressed the studies that focus specifically on gender, the socially constructed roles and identities held by people across our society. Though funders like CIHR have mandated the need for gender-specific analyses, there is also much work to be done to improve the measurement and investigation of these effects.
For more information about sex, gender, and research, see our Clinical Research 101 post on the topic.
Liu KA, Mager NA. Women’s involvement in clinical trials: historical perspective and future implications. Pharm Pract. 2016;14(1):708.
Canadian Institutes of Health Research. Sex, Gender and Health Research. Government of Canada. Last modified: 2019 Nov 22.