Low Angle Best Friends Looking Down (1)

The Under-representation of Women in Clinical Trials

The Under-representation of Women in Clinical Trials

  • Reading time:6 mins read

Clinical trials are the cornerstone of evidence for new medical therapies. However, a persistent issue shadows the reputation of these medical advancements: the under-representation of women in clinical trials.

A short history on women in medical research

For too long, there was an assumption that no fundamental difference existed between men and women, other than size, weight, and reproductive organs. This led to early medical research being predominantly focused on men.
On top of this, the year 2023 marks only 30 years since the retraction of a policy issued in the 1970s by the United States Federal Drug Administration (FDA) recommending the exclusion of women with childbearing potential from early phase clinical trials.

Reproductive toxicity and potential adverse foetal developments were the driving factors behind the FDA policy barring women of child-bearing potential from clinical trials. The now infamous drug, thalidomide, had devastating consequences on foetal development when mothers were prescribed this drug to combat morning sickness in the 1950s and 1960s.

This prompted a climate of caution and protectionist agendas from both pharmaceutical companies and the government when considering the eligibility of women in clinical research. The FDA policy was broad, with even women who were on contraception, single women, or women whose husbands were sterilised also excluded from participating in early phase trials.

This problematic approach of treating women under an “anticipatory motherhood” assumption has created barriers for the ability of women to participate in clinical research that are seen to this day. Additionally, the consequences of under-representing an entire sex for nearly two decades have been far-reaching in the medical field.

Consequences of excluding women from clinical trials

We now know that women have different drug metabolic profiles and are more likely to experience adverse drug reactions than their male counterparts, yet safety and tolerability data is often modelled from male populations. In 2013, the US FDA intervened to amend the dosage of medications containing zolpidem, the active ingredient found in the popular sedative drug Ambien. After twenty years on the market, it was found that the dosages, based on men, should have been lower for women to reduce the risk of harm, such as prolonged cognitive impairment.

Along with an inaccurate understanding of drug efficacy and safety in women, there has been delayed knowledge and inadequate treatment options for women’s health conditions. Diseases such as endometriosis and polycystic ovary syndrome (PCOS) have received less research attention due to the lack of female participants in clinical trials. This bias hampers the development of tailored treatments and therapies, causing those with the diseases to have very limited treatment options.

Despite the strides in knowledge gained over the years about the biological and metabolic differences between the sexes, there remains a male bias in basic, preclinical, and clinical research that has been correlated to women experiencing suboptimal healthcare and adverse medical outcomes.

For example, cardiovascular disease is a leading cause of death in women, yet women make up only 38% of participants in cardiology trials. As a result, typical symptoms of a heart attack were based on male patients and recognised as chest pain, shortness of breath, and light-headedness. It is now known that women present much differently, with their typical symptoms consisting of fatigue, nausea, and stomach pain, along with chest pain. As a consequence, women were 50% more likely to be misdiagnosed following a heart attack, increasing their risk of death.

So where are we now?

Despite the FDA reversing its policy and the National Institutes of Health (NIH) passing a law that required the inclusion of women in NIH-funded trials in the early 1990s, the representation of women in clinical trials remains an issue to this day. A recent study has highlighted the fact that women are still under-represented in clinical trials for cardiology, oncology, neurology, immunology, and haematology. Efforts to close the sex imbalance in clinical research are underway.

Regulatory bodies, such as the NIH, have begun emphasising the need to include diverse populations, encouraging researchers to enrol more women in their studies. Initiatives promoting awareness and education among both healthcare providers and the public about the importance of female representation in research are gaining traction. Furthermore, there is a growing call for more flexible trial designs that accommodate the unique needs of women, including considering different hormonal phases and variations in responses to treatments.

At Elion Medical Communication, we support medical communications agencies and pharmaceutical and medical device companies with medical writing services. We can help you publish your clinical research. To find out more or if you have a project in the pipeline, get in touch.

Photo credit

Ana Holley