Women Are Underrepresented in Clinical Trials, Leading to Health Inequity

Contemporary Clinical Trials published a study by researchers at the Brigham and Women’s Hospital that shows women were underrepresented in clinical trials. This conclusion may be contributing to gender health inequity. 

To conduct the analysis, the researchers looked at clinical trials from the clinical trial database from 2016 to 2019 and compared participant data to prevalence data. They narrowed their focus to drug trials for cardiovascular, psychiatric, or cancer-related illnesses using the provided data.  

According to the CDC, cardiovascular disease and cancer are the leading causes of death in the United States. The research identifies that this fact is the same when looking at just the female gender. Furthermore, psychiatric disease impacts a large portion of women.  

The results uncovered an underrepresentation of women in clinical trials for all three diseases. Compared to the 49% of people with cardiovascular disease who are women, only 41.9% of clinical trial participants for cardiovascular disease medications were women.  

Similarly, 51% of cancer patients are women, but drug trials only had a female participation rate of 41%.  

The starkest lack of portrayal was in the psychiatric studies. While 60% of psychiatric patients are women, only 42% of psychiatric clinical trial participants are women.  

Clinical trials are multi-faceted and require many criteria, including a diverse demographic, which many trials lack.  

The limited representation of women in clinical trials has many implications for women's health equity and overall disease outcomes.  

An article published in the American Family Physician Journal found significant differences in how women absorb, distribute, metabolize, and excrete drugs. Additional studies have also found that women have differing adverse side effects to medications and experience these side effects at higher rates.  

The WHO highlights and plans to address the focus on men while developing drugs, treatment plans, and vaccinations in a 2021 press release.  

Diversifying patient populations is something that several pharmaceutical industries have been considering recently.  There is not only a lack of gender diversity but also inequitable participation in clinical trials across races.  

The study concludes, “given potential sex-based differences in treatment responses and toxicities, adequate inclusion of females in clinical trials remains critical.” 

Diversification of clinical trial demographics may shape the way providers dose and prescribe medications. Beyond the three illnesses considered in this study, additional research on gender composition and sexually dimorphic response is indicated.