The science that informs medicine -- including the prevention, diagnosis and treatment of disease -- routinely fails to consider the critical impact of sex and gender. These omissions exist at the same time diseases such as lung cancer, heart disease, Alzheimer's Disease and depression profoundly impact women illustrating the effect of inequitable science on women's health and sex differences in medicine. As national organizations representing patients who suffer from these diseases, the American Heart Association, the Lung Cancer Alliance and Women Against Alzheimer's are joining forces against this pervasive problem that transcends diseases, and threatens the overall health of all Americans.
A report released in March, "Sex Specific Medical Research: Why Women's Health Can't Wait," co-authored by The Connors Center for Women's Health and Gender Biology at Brigham and Women's Hospital and The Jacobs Institute at George Washington University, found that two decades after a landmark law mandating the inclusion of women in biomedical research, sex-specific research is still the exception, not the norm. This means that women are receiving recommendations from their providers regarding diagnosis, prevention strategies and medical treatments based on research that has not adequately included or reported results on women.
This begins in the earliest stages of research, when females are excluded from animal studies or the sex of the subjects/animals is not stated in the published results. This continues into human studies. Once clinical trials begin, researchers frequently do not enroll adequate numbers of women. When they do, they fail to analyze or report data separately by sex. In looking at four specific disease areas, here's what the authors found:
Cardiovascular disease is the number one killer of both women and men in the United States, yet less than one-third of cardiovascular clinical trial subjects are female and less than one-third of cardiovascular clinical trials that include women report outcomes by sex.
More women die of lung cancer annually than from breast, ovarian and uterine cancers combined. Among non-smokers with lung cancer -- which takes nearly 30,000 lives each year -- three times as many women are diagnosed compared to men. As a general matter, lung cancer is the subject of inadequate research. But even when studies take place, researchers often fail to analyze data by sex or include sex-specific factors, making it difficult to uncover differences in incidence, prevalence and survivability between men and women.
Depression is the leading cause of disease burden worldwide. Twice as many women than men suffer from depression in the U.S., yet fewer than 45 percent of pre-clinical studies on anxiety and depression use female animals, studies that are the basis of drug discovery.
Even though a woman's overall lifetime risk of developing Alzheimer's disease is almost twice that of a man, the prevailing thinking in the field is that this is simply because women live longer. However, differences in women and men's brain structure and function and the pathology of the disease are well established. The impact of hormones have begun to emerge as potential explanations as well.
The most troubling aspect to these statistics is that we continue to ignore why they occur. We know that men and women present differently for many diseases and may react differently to treatment strategies and drug dosages. To ignore these differences undermines the quality and integrity of science and medicine and the ability to deliver the right care to the right patient at the right time.
The alarm sounded by this new report has brought together important forces to address this problem. The report calls for a multi-stakeholder approach to advancing a Women's Health Equity Plan which involves movement on many fronts including: stronger government accountability from all agencies funding medical research; better transparency and disclosure regarding the absence of sex- and gender-based evidence in research, drugs and devices; warning labels if clinical testing fails to include adequate numbers of females; and for scientific journals to encourage the reporting of the sex of lab animals and human subjects as well as sex-specific results. Our organizations have joined with the Connors Center for Women's Health and other supporters to move the Women's Health Equity Plan forward. We have participated in the process by working with champions in Congress and the Food and Drug Administration on an Action Plan that addresses gaps in the participation of women, minorities and the elderly in clinical drug trials.
We applaud the recent call by members of Congress requesting that the Government Accountability Office study the inclusion of women in NIH-supported clinical trials to understand whether the level of participation is sufficient for researchers to provide meaningful results. And we commend NIH's policy change, announced this week, requiring the balanced inclusion of both male and female animals and cells in preclinical studies. As we continue to advocate for our specific disease areas, we will work together to make sex-differences in science a key part of all our agendas.