Addressing Gender Differences: Clinical Drug Trials
Erin Fredericks
Aspirin, a common over-the-counter painkiller, was released in 1897. Since then, thousands of scientific papers discussing the benefits of the drug had been published worldwide. A considerable number of these studies demonstrated that taking a low, daily dose of Aspirin can reduce the risk of stroke or heart attack. Great news for people at risk; however, the focus on this benefit has overshadowed the fact that these studies have not answered all the important questions about this drug.
In 2005, Rob Stein of the Washington Post reported the results of a 10-year study that assessed the benefits to women taking daily doses of Aspirin. This study was the first to focus on Aspirin’s affects on women, many of whom had begun taking Aspiring based on the reported benefits to men. Stein reported that the study showed that Aspirin does not protect women from heart attacks in the same way it does men. In fact, the risks of the daily dose to healthy women in their forties and fifties may outweigh the benefits. The lead researcher of the study, Julie Buring, was quoted as saying “This truly underscores the importance of studying medical therapies among women as well as men. We can't assume studies involving men apply to women."
In 2007, CBC news reported the findings of a twenty-four year observational study of the benefits of daily aspirin intake to women aged forty-five and above. The results show that Aspirin does not protect women in the same way as men, but does have benefits for women over sixty and those at moderate to high risk for heart disease or stroke. Dr. Beth Abramson of the Heart and Stroke Foundation of Canada stated that these results may be due to the fact that “women develop heart disease and stroke on average seven to ten years later than men”.
The case of Aspirin is by no means an extraordinary one. And while these studies do not imply that young women should stop taking headache medication, it serves as a reminder that we should look past the face value of scientific studies and ask critical, relevant questions about the purpose of medical studies. In this instance, and in many more, the answers demonstrate that the biological and gender differences between women and men continue to be overlooked.
The biological, or sex, differences between women and men are physical and physiological. Differences such as weight, hormones, body fat percentage, heartbeat speed, and stomach emptying speed can affect how women and men react to pharmaceuticals. Therefore, it is necessary to test new drugs and new indications for drugs on both females and males.
Biological differences do not explain why women have been, and continue to be, excluded from many clinical trials. Women differ from men in terms of both sex and gender. It is gender inequality—the relative power society has given to men and women—that explains the continued exclusion of women from drug trials.
The exclusion of women from clinical trials can negatively affect women’s health. First, clinical trials allow study participants access to new and innovative technologies that may treat or cure an illness. When women are excluded from clinical trials they are also denied access to new treatments. Second, women may be taking medications that are not proven to be effective or even safe for them. Positive results from clinical trials with male participants do not always apply to women. Third, the inclusion of one sex and not another reinforces inequalities. The exclusion of women from clinical trials is often seen as a way of “protecting” women from possible side effects.
In response to the negative health affects of excluding women from clinical trials, the Canadian Government released Inclusion of Women in Clinical Trials in 1997. This policy suggests that patients of both sexes be included in the same trials to allow detection of clinically significant sex-related differences in drug response. Also, the policy suggests that researchers include measures of the influence of the menstrual cycle and estrogen-based medications on the drug’s effects, and the influence of the drug on oral contraceptives.
In recent years, the number of women in many drug trials has increased. But again, these trials may not be answering all of the important questions. However, in a 1998 review of clinical trials of heart attack drug therapy, Rochon et al. found that only 32 percent of the trials that included female participants reported sex-specific results. Inclusion is a step in the right direction, but it is certainly not the end of the line. We gain little knowledge from inclusion unless it is accompanied by sex-specific analysis and results.
A closer look at clinical drug trials teaches us an important lesson. In our quest to achieve equality, we must not overlook the differences and inequalities that currently affect our health and safety. In our society, women are different from men both biologically and socially. We must accept and address the biological differences we cannot change. While we should not accept social inequality, or see it as inevitable, we must recognize the need for policies and programsthat address the social inequalities that still exist.
Photo Credit: All Aspirin Photos courtesy of Devin Pulsifer (all permissions granted).
References & For More Information:
CBC News. (2007, March 26). Older Women Benefit from ASA: Study. CBC News Online.
Dresser, R. (1992). Wanted. Single, white male for medical research. Hastings Centre Report. 22(1): 24-29.
Health Canada. (1997). Inclusion of Women in Clinical Trials. Therapeutic Products Directorate, Health Canada: Ottawa.
Rochon, P.A., J.P. Clark, M.A. Binna, V. Patel & J.H. Gurwitz. (1998). Reporting of gender-related information in clinical trials of drug therapy for myocardial infarction. CMAJ. 159: 321-327.
Stein, R. (2005, March 8). Aspirin's Benefits Differ for Women: Strokes Averted, Not Heart Attacks. Washington Post, p. A01.
Women and Health Protection. (2006). The Inclusion of Women in Clinical Trials: Are We Asking the Right Questions? Bureau of Women’s Health and Gender Analysis, Health Canada: Ottawa.
