Each of these circles represents a disease, with circle area representing disease burden — a measure of how much death and disability it causes.
Grey circles represent diseases that affect men and women roughly equally.
For orange circles, at least 60% of people with the disease are women.
For blue, at least 60% of those affected are men.
Light blue and light orange circles represent diseases in which men or women, respectively, are slightly dominant, from 55% to 60%.
Of the conditions that are dominant in one sex, those that create the highest burden, such as depression and headaches, tend to affect women more.
Here are the diseases ranked by burden.
Now let’s look at funding data from the US National Institutes of Health (NIH), which spent US$45 billion on biomedical research in 2022. If NIH funding were determined only by the burden of disease, these bubbles would remain in the same size order.
Instead, when ranked by funding amount, diseases that affect mainly women drop down. They are underfunded compared with the burden.
Migraine, headaches, endometriosis and anxiety disorders, for example, which disproportionately affect women, all attract much less funding in proportion to the burden they exert on the US population than do other conditions.
HIV/AIDS and substance misuse, which disproportionately affect men, get more funding than their corresponding burden might suggest.
The degree of underfunding or overfunding is different for the groups of conditions, too. On average, female-dominant diseases that are underfunded are more severely so. For chronic fatigue syndrome, also known as myalgic encephalomyelitis (ME/CFS), for example, the ratio of burden to funding is 0.04. For HIV/AIDS, the ratio is 15.6.
Source: Ref. 1
These results come from the work of US applied mathematician Arthur Mirin, an independent researcher who initially published the analysis1 in 2021. The data shown here are from his updated analysis of the latest NIH information on funding and burden. The overall pattern remains the same.
The 2021 analysis “demonstrates that the funding of research for women is not aligned with burdens of disease”, says Sarah Temkin, associate director for clinical research at the NIH Office of Research on Women’s Health in Bethesda, Maryland.
Neuroscientist Liisa Galea, at the Centre for Addiction and Mental Health in Toronto, Canada, who has published on female representation in science, is not surprised by the findings of Mirin’s study on funding for women’s health. “Unfortunately it is really undervalued, understudied.”
In an e-mail to Nature, the NIH also said that it takes into account considerations beyond the burden of disease when making funding decisions, for example for urgent research that might mitigate an outbreak of infectious disease.
Mirin is not the only one to make such observations. A smaller analysis2 of cancer funding, using data from the US National Cancer Institute over the 11 years from 2007 to 2017, showed that gynaecological cancers receive much less support than do other cancers when accounting for lethality (years of life lost for each new diagnosis). In a selection of 19 cancers, ovarian cancer ranks 5th for lethality, but 12th in terms of its funding-to-lethality ratio. Cervical cancer followed a similar pattern. For many gynaecological cancers, the ratio of funding to mortality dropped during the 11-year period.
Although other public funding agencies outside the United States don’t provide such granular detail, one team of researchers looked at almost 9,000 grants3 awarded by the Canadian Institutes of Health Research, the country’s main funder of such research, from 2009 to 2020. They found that 5.9% of grants looked at female-specific outcomes, although the grants were worth more on average in 2020 than in 2009.
The UK Medical Research Council (MRC) provided Nature with figures on its funding for women’s health, which includes research on preterm birth and perinatal health, and long-term studies such as the Million Women Study, which investigates the effects of diet, smoking and other factors on disorders including cancer and heart disease. The funder spent £96 million (US$119 million) on this area in the 5 years from 2014. That was roughly equivalent to its spending on cardiovascular disease alone in the same period (the MRC spends about £325 million a year on health research overall). Galea, who studies depression and Alzheimer’s disease, among other disorders, says women’s health funding should cover more than just female-specific conditions. “Every single organ in our body is affected by our sex,” she says. “It affects every part of our health.”
Women have been historically under-represented in other parts of the medical research pipeline, such as clinical trials. The same is true for female animals in basic research.
“It takes a long time to recover from the gaps in the evidence base that resulted from exclusion,” says Temkin.
Work to rectify the bias in clinical research is paying off in some places: by 2014, about half of all participants in clinical trials funded by the NIH were women. But even so, women are not necessarily included in proportions that match the prevalence or burden of disease.
For instance, in the United States, women comprised 42.9% of participants in oncology clinical trials between 2000 and 2020, but experienced 46.5% of the burden4. In neurology and immunology, too, women were under-represented. In some conditions, such as musculoskeletal disease and trauma, they were over-represented.
In this study of more than 20,000 clinical trials in the United States between 2000 and 2020, women were under-represented in some trial types and over-represented in others. The study compared participation rates with the burden of disease, measured in disability-adjusted life years (DALYs), which account for the disability and death caused by a disease.
For instance women comprised 42.9% of participants in oncology clinical trials between 2000 and 2020, but experienced 46.5% of the burden4. In neurology and immunology, too, women were under-represented.
In some conditions, such as musculoskeletal disease and trauma, they were over-represented.
Source: Ref. 4
In a similar analysis of clinical trials of drugs approved between 2011 and 2015 in Europe, women made up 41% of participants overall5.
In some areas, such as depression and diabetes, the proportion of women included was appropriate for the disease prevalence. But they were particularly poorly represented in trials of therapies for heart failure and schizophrenia, among others.
What if funding for women’s health increased? That was the question behind a series of reports commissioned by the non-profit advocacy group Women’s Health Access Matters (WHAM) in Greenwich, Connecticut.
It worked with researchers from the RAND Corporation, a non-profit research and policy organization based in Santa Monica, California, to run simulations that looked at the likely return on investment for increasing funding of women’s health6.
They chose four conditions that affect women disproportionately, or in which women tend to experience different symptoms from men, and which were not related to reproductive or maternal health: rheumatoid arthritis, coronary artery disease, Alzheimer’s disease and lung cancer. “Research shows that many of these diseases affect women differently, specifically, predominantly,” says Carolee Lee, founder and chief executive of WHAM.
Across the four diseases, the NIH budget for women-focused research was $350 million. The study modelled what might happen if that doubled, and assumed that this increase would deliver a slight (0.01%) improvement to health in terms of life expectancy, disease progression and quality of life.
For coronary artery disease, for example, the budget boost was projected to save nearly 20,000 life years and almost 40,000 years with disease for women over a 30-year period.
Source: Ref. 6
The study also looked at the return on investment from a boost in funding. For rheumatoid arthritis, for instance, the study assumed a 0.1% health improvement, which had huge impacts on quality of life and productivity that together reduced the costs of the disease by around $10.5 billion over 30 years, equating to a staggering 174,000% return on investment.
This graphic shows the projected increase in productivity and quality of life, measured using a metric called quality-adjusted life years (QALYs). QALYs incorporate both length of life and the quality of that life. One QALY is equal to one year of life in full health, and health economists can assign a monetary value to a QALY by estimating how much each extra one costs to generate — or how much is saved by reducing them.
Lee says that WHAM is now running a global study of women’s health-research funding, including the United Kingdom, France, Italy, Israel and Japan.
Efforts are under way to offset the gender gap in funding. The NIH, for example, has allocated $10 million to set up an Office of Autoimmune Disease Research, as recommended in a report requested by Congress. Women constitute nearly 80% of people with autoimmune diseases. And in May last year, two US Democratic members of Congress from Illinois, Senator Tammy Duckworth and Representative Jan Schakowsky, introduced a bill calling for a doubling of investment in women’s health research.
Galea says that funding specifically for women’s health would draw more researchers’ attention to the area. “If you put a pot of gold at the end of a funding rainbow, researchers are going to go for it.”
Kerri Smith is a Features editor at Nature in London.
This article is also available as a pdf version.
- Mirin, A. A. J. Womens Health 30, 956–963 (2021).
- Rush, S. et al. Gynecol. Oncol. 162 (Suppl. 1), S322–S323 (2021).
- Stranges, T. N., Namchuk, A. B., Splinter, T. F. L., Moore, K. N. & Galea, L. A. M. Preprint at bioRxiv https://doi.org/10.1101/2022.11.30.518613 (2022).
- Steinberg, J. R. et al. JAMA Netw. Open 4, e2113749 (2021).
- Dekker, M. J. H. J. et al. Front. Med. 8, 643028 (2021).
- Baird, M. D. et al. The WHAM Report: The Case To Fund Women’s Health Research (RAND & WHAM, 2022).