- A new analysis suggests that while women and men have an equal lifetime risk of stroke, only 37% of participants in clinical trials of stroke treatments are female.
- This gender bias could make the findings of some trials unreliable for female patients, who tend to experience more severe impairment after a stroke.
- The authors of the analysis conclude that researchers should address the barriers that prevent women from enrolling in their studies.
During aย stroke, the blood supply to part of the brain is interrupted, or a blood vessel in the brain bursts. This deprives the affected region of oxygen and nutrients, which can result in the death of some brain cells.
Acute symptoms of strokeTrusted Sourceย include numbness or weakness on one side of the body, difficulty speaking and understanding speech, and problems with vision.
Theย Centers for Disease Control and Prevention (CDC)Trusted Sourceย reports that more than 795,000 people have a stroke every year in the United States. Someone has a stroke every 40 seconds, and every 4 minutes, someone dies from a stroke.
Research suggests the global lifetime risk of stroke from age 25 onwards is approximatelyย 25%ย among men and women.ย Women also tend to experienceย more significant disability and worse quality of lifeย as a result of a stroke.
However, a new study suggests that women are underrepresented inย clinical trialsย of treatments.
โOur findings have implications for how women with stroke may be treated in the future, as women typically have worse functional outcomes after stroke and require more supportive care,โ says study authorย Cheryl Carcel, M.D.,ย of The George Institute for Global Health in Sydney, Australia.
Julie Anne Mitchell, director of health strategy at the National Heart Foundation of Australia, toldย Medical News Todayย that the underrepresentation of women inย cardiovascularย research was a long-standing problem.
โUntil recently, the default position has been to conduct studies on male cells, male animals, or male humans, and then apply these findings to women,โ she said. She added:
โThe risk [โฆ] in doing so is that vital pieces of information โ such as the influence that hormones, body size, or menstruation might have on treatment options and outcomes โ will be missed.โ
The research appears inย Neurology, the journal of the American Academy of Neurology.
The researchersย analyzedย 281 trials of stroke treatments that took place between 1990 and 2020 and involved a total of 588,887 participants. In the countries where the trials took place, 48% of all strokes occurred in women. But only 37.4% of the total 588,887 trial participants were female.
Women had the worst representation in trials involving a type of stroke known asย intracerebral hemorrhageย and trials investigating rehabilitation after a stroke.
โMaking sure there are enough women in clinical studies to accurately reflect the proportion of women who have strokes may have implications for future treatment recommendations for women affected by this serious condition,โ says Dr. Carcel.
โWhen one sex is underrepresented in clinical trials, it limits the way you can apply the results to the general public and can possibly limit access to new therapies,โ she adds.
The representation of women in clinical trials did not appear to have changed over the course of the 3 decades studied.
When researchers design a clinical trial, they may set a goal for the number of women to enroll in order to get statistically significant findings about the treatment in women.
โIf the target number of women isnโt enrolled in the trial, then they might not give the medication to women,โ said co-first authorย Katie Harris, Ph.D., of The George Institute for Global Health.
โ[T]his may actually preclude women from receiving a new therapy that can save their life or make them live longer,โ Dr. Harris toldย MNT.
In addition, women tend to be older when they have a stroke, so the upper age limits for enrolment in some clinical trials may reduce their representation.
โResearchers could also promote for data to be sex-disaggregated when their work is published in a journal so that such presentation of data becomes the norm rather than the exception,โ she said.
She added that longer trials with more follow-ups may be impractical for women who are responsible for the care of children, grandchildren, or partners.
Dr. Sonya Babu-Narayan, a consultant cardiologist at Royal Brompton Hospital and associate medical director at the British Heart Foundation, agreed.
โWe know that some requirements for participating in clinical trials, such as repeated visits to hospital for research appointments over months or years, can be difficult for women with commitments to care for children and elderly relatives,โ she toldย MNT.
โThe situation may be compounded further by persisting misperceptions that heart disease is a manโs disease,โ she added.
In a statement, the American Heart Association toldย MNTย that it now only funds research that is fully inclusive of women. The statement continued:
โIn 2019, the American Heart Association launchedย Research Goes Redย [โฆ] to engage more women in research and create the worldโs most engaged and largest womenโs health registry and platform for research. The leadership of the association believes that part of the solution to this is also to engage more women in STEM [science, technology, engineering, and mathematics] careers and research jobs.โ
