When it Comes to Medical Research — We Are Not All Created Equal

March 13, 2014

Disease is the great equalizer. For example, heart disease doesn’t care about your gender, race or economic status. But the science that informs medicine — medical research, including the diagnostics and treatment of disease — is unequal. Most medical research fails to account for how gender differences in diseases impact who remains healthy, who becomes ill, and how the illness is best treated.

The Revitalization Act of 1993, passed by Congress and signed into law by President Clinton, set the stage for major advances in women’s health. Yet, despite the expanded inclusion, disparities remain regarding women and minorities, including: a shortage of research on gender differences in disease and on health problems that disproportionately impact women; the insufficient inclusion of women and minorities in research and clinical trials; and the failure to report outcomes of research by sex.

In a report released this month, by Brigham and Women’s Hospital, on the future of women’s health, more transparency in research on drugs and medical devices was recommended, and suggested that clinical trials should carry a disclaimer if a study has not included enough female participants.

While women are now more routinely included in clinical trials and an entire field of women’s health has emerged beyond reproductive health, there are still enormous gaps in the scientific process as it relates to women. Basically, unless you study the populations that you’re treating, you really don’t know how that population is going to respond.

The latest statistics are disappointing:

  • Less than one-third of cardiovascular clinical trial participants are women, and only one-third of trials that include women report sex-specific outcomes. Yet, cardiovascular disease is the number one cause of death among U.S. women.
  • Less than 45 percent of animal studies on anxiety and depression use female animals, although depression is a leading cause of disease among women worldwide.
  • Lung cancer researchers often fail to include an analysis of data by sex or gender-specific factors, despite the fact that lung cancer behaves differently in nonsmoking women than in nonsmoking men. This disease kills more women each year than breast, ovarian and uterine cancers combined.
  • A woman’s overall lifetime risk of developing Alzheimer’s disease is almost twice that of a man, and it has been thought that this is simply because women live longer. However, hormones may play a role.

Twenty years later, it is alarmingly apparent that The Revitalization Act only began to solve a major shortfall in research.

Women are still not included in clinical research in numbers reflecting the pervasiveness and impact of disease in women. This means that current clinical practices, including treatment guidelines and medication dosages, are derived largely from research done on men. In spite of including both women and men in clinical research, 66 percent of studies including both sexes fail to analyze the data by sex, which could show a difference between men and women in the treatments or dosages needed to have the best results.

Even at the very early stages of scientific research — animal studies — sex is not considered. For example, the majority of studies using laboratory animals to study neuroscience pharmacology and physiology, where findings are more likely to translate to humans, only use male mice.

Women face safety concerns when it comes to prescription drugs. Eight of the ten drugs withdrawn from the market between 1997 and 2000 had higher risks for women compared with men. A lack of research focused on sex differences in disease and therapeutics may contribute to these differences.

Twenty years of experience since the Revitalization Act, along with major changes in science and technology, and our current knowledge of gaps in implementation, demand an examination of the legislation’s sphere of impact, a reexamination of its components, and the consideration of new strategies.