The perils of ignoring gender in health and medical research
Special surfboards for women?
In 1987, federal opposition leader John Howard gave a pre-election policy speech focusing primarily on what he saw as the government’s economic mismanagement and wastefulness. One of his examples of financial irresponsibility was a grant of $11 000 to a firm intending to develop a special surfboard for women. Of course, Mr Howard could hardly have been expected to foresee that later the same year Australia’s Wendy Botha would win the world surfing championship, that Australian women would dominate the world professional surfing circuit in the foreseeable decades (winning 20 of the following 29 titles), and that a female-specific surfboard would soon become commonplace.
Special surfboards for women are not very obviously related to Western Alliance’s usual health focus (despite the undeniable health benefits of surfing), but the point is a serious one. It’s unfortunately the case that sporting equipment, machinery, medicines and many other products and procedures are designed primarily for men but are marketed or represented as suitable for women. The problems with this male-first approach can manifest as anything from annoyance or inconvenience to significant health risks for women. In this edition of In Brief we explore the benefits of evidence-based, gender-specific design.
Yes, special surfboards for women
To return to the surfing example, most women are smaller and lighter than men, and so find it challenging to surf well on the large and heavy boards designed for men. Surfboards designed with women in mind are smaller, lighter and shaped to suit the needs of the female surfers.
This shift in sporting equipment design is extending to other sports, with the development of female-specific football boots, basketball shoes and cricket bats. The idea driving this change is that possessing a surfboard, footy boots or other sporting equipment to match your physical characteristics provides greater comfort, reduces fatigue and thereby reduces risk of injury.
Female firefighters in men’s clothing
Firefighters undertake heavy manual labour under extremely hot and often humid conditions, and must wear high-performance protective clothing to avoid heat stress. In Australia, female firefighters wear the same protective clothing as men, but in smaller sizes. This is a problem because, according to tests undertaken by Nasia Nawaz, Olga Troynikov and Kate Kennedy of RMIT University with male-specific protective clothing, the female form traps more air between the body and the clothing than the male form, reducing its thermophysiological performance. Other researchers have found that female firefighters are nearly four times as likely as men to report problems with ill-fitting equipment.
The implication is that female firefighters are at heightened risk of heat stress due to having to wear clothing designed for men. Men greatly outnumber women in this sector, so the population affected is small and the costs of providing female-specific equipment relatively high, but this is hardly a justification for women having to use equipment that seems likely to be a health risk. Moreover, the number of women drawn to the profession is increasing: in 2016, women made up 50 per cent of the graduating class of Fire and Rescue New South Wales.
Female representation in medical research
Medical research is another field in which women effectively have been regarded as ‘small men’ – meaning that researchers have tacitly assumed that results obtained using mostly or mainly male humans and animals will also apply to females, but at lower ‘doses’. Despite long recognition of the differences between male and female physiologies, and in their responses to disease, biomedical researchers continue to use many more male than female subjects in both animal studies and human clinical trials. The effect of this discrepancy is that the medicine currently being applied to women has less evidence to support it than that being applied to men.
For example, a great deal of medical research is performed using mouse models, and overwhelmingly involves male mice, yet substantial variations in gene expression exist between male and female mice. Irving Zucker and Annaliese Beery (University of California) reviewed almost 2000 animal studies published in 2009, and wrote that:
… diagnoses for anxiety and depression are more than twice as common in women than in men, but fewer than 45 per cent of animal studies into these disorders apparently used females. Women have more strokes than men, with poorer functional outcomes, but only 38 per cent of animal studies into strokes used females. Some thyroid diseases are seven to ten times more common in women, but only 52 per cent of animal models used females.
This practice continues despite hundreds of studies in many fields demonstrating that research using female animals is valid and reliable. Research into epilepsy and multiple sclerosis, diseases well known to be influenced by ovarian steroids, commonly involves female animal models.
Gender and cardiovascular disease
Heart disease is the leading cause of death in men and women in Australia and many highly developed countries. However, survival rates are lower in women than in men, even after accounting for age. Within five years, 47 per cent of women in the United States who experience a first heart attack will die, develop heart failure, or suffer a stroke, compared with 36 per cent of men.
A plausible reason for this difference was revealed in a cohort study of 49 358 patients admitted to 366 hospitals in the United States for heart disease (usually a heart attack). The authors found that women were less likely than men to receive potentially beneficial medications such as aspirin and cholesterol-lowering medications, or to receive advice about quitting smoking.
Another explanation for high female mortality due to heart attack is that while most patients present with chest pain or chest discomfort, women often present with atypical chest pain and symptoms such as weakness, fatigue, difficult or laboured breathing, and indigestion. Hence, gendered differences in clinical presentation interfere with timely identification of cardiovascular symptoms and appropriate management.
How might we best address gender issues in medical research?
In The Conversation (17 August 2017), Associate Professor Deb Colville (Monash University) wrote:
We need data from clinical trials and population data that is sorted by gender, so knowledge bases can be gradually improved. Generalisations about gender can be both useful and problematic, so careful analysis is needed.
Professor Colville argued that gender should be recognised in all medical training and clinical practice – not only in disciplines that relate to sex hormones such as gynaecology, but also in areas such as orthopaedics and ophthalmology, in which gender differences are substantial (for example, nearly two-thirds of the world’s blind people are women).
She concluded with a call for the medical profession to take the lead in taking account of gender diversity in the Australian community, including introducing targets for diverse representation on all professional decision-making bodies.
The physiological differences between men and women are significant in many respects; ignoring them presents risks to women’s health. Researchers need to be more mindful of gender and take appropriate account of female physiology and female participation in research. Neglecting gender in research weakens the evidence base that underpins health interventions and initiatives.