Improving Medical Education Using a Sex- and Gender-Based Medicine Lens

Introduction

The discipline of Sex- and Gender-Based Medicine (SGBM) evolved from the field of Women's Health, which itself emerged as a result of the women's health movements in the latter part of the twentieth century. ¹ In SGBM, the similarities and differences in both women and men are explicitly considered to better understand disease processes and healing. This broader framework will stimulate future research and lead to the integration of clinically applicable research into medical education and practice.

Sex and Gender Limitations in Research and Medical Education

The NIH Revitalization Act of 1993, which mandated the inclusion of women and minorities in clinical trials, led to more research with those populations, ultimately demonstrating that there are significant sex and race differences in disease and health. ² After the results of the NIH funded Women's Health Initiative research were published, a body of scientific knowledge specific to women's health accrued in many domains. However, a recent NIH audit by the U.S. Government Accountability Office indicated that while more women than men were enrolled in NIH funded clinical research between 2005 and 2014, the NIH does not have tracking processes in place to determine whether the research has been analyzed for potential sex differences. ³

Despite the fact there is now a great deal of scientific research showing that women's health differs from men's health in many ways and vice versa; sex and gender differences tend to be marginalized in medical education and, consequently, are not integrated into clinical practice. ^{4 –6} A recent national medical student survey showed that many common sex and gender differences were not included in medical school curricula. ⁷ These problems are due primarily to a lack of awareness about sex and gender issues in health.

Women's health is marginalized when we incorrectly equate women's health with reproductive health and link women's health solely with the specialty of obstetrics and gynecology. Although there are now many who envision women's health more broadly as referring to the whole body, pervasive traditional beliefs about women make it difficult for many researchers, practitioners, and educators to adopt a more holistic approach toward women's health. These problems can be addressed by broadening our conceptualization of health differences between males and females beyond reproductive health and by explicitly adopting a sex and gender lens in research, education, and practice. In addition, men must also be viewed as gendered beings who engage in gendered behaviors that have consequences for their health.

A Sex and Gender Lens

There is confusion about the terms sex and gender. Researchers, scholars, and lay individuals often use the terms sex and gender interchangeably. Many researchers will refer to gender differences when what is meant is a biological sex difference. ⁸ Gender is often construed as a politically correct term for biological sex. Furthermore, the field of gender studies often focuses on women's issues and sociocultural perspectives, partly due to the need to remedy the historic lack of attention to women's experiences and views. This creates an association between the terms gender and women, and in the minds of many, it equates the term gender with women.

While such views are changing, especially among younger adults, it is still easier to think of women as being gendered while it is more difficult to recognize that men are also gendered. In such a framework, men are normative and women are explained in terms of how they differ from men. For example, it is often reported in both healthcare domains and consumer awareness campaigns that women are more likely to present with “atypical” presentations of heart disease. ⁹ This is due, in part, because early cardiovascular studies predominantly included middle-aged white males so that the normative presentation of ischemic heart disease became crushing chest pain radiating down the arm that perhaps also includes shortness of breath and nausea.

Sex and gender are foundational characteristics of all humans and both are foundational to understanding health and illness. ¹⁰ In broad terms, sex is a biological construct that refers to the characterization of living things according to reproductive organs and chromosomal complement. ¹¹ The appropriate terms are male, female, or intersex, where intersex refers to a discrepancy between external and internal genitals. ¹² Gender refers to a person's self-representation and behavior as man or woman within the context of social structure and culture. ^11,13 When one's gender identity (how a person views themselves) crosses or transcends one's biology, such individuals are referred to as transgender. ¹⁴

Societies are organized based on gendered expectations, opportunities, and roles for men and women. When individuals deviate from these expectations, they often face sanctions. In many societies, men's gendered domain has been associated with work while women's gendered domain has been associated with the home. Specific expectations vary across countries, communities, socioeconomic status, race, ethnicity, religion, life stage, subculture, and historical time.

There are many variations in how individuals express their gender. They may choose to act in ways that are culturally defined as more masculine in some situations and more feminine in others, for example, while at work versus while parenting. Despite this variability, there are broad patterns of gendered behaviors that have health consequences. ¹⁵ For example, men are more likely to play football or be firefighters, while women are more likely to play softball or be employed in administrative support roles.

Sex and gender are analytic concepts, meaning they are typically conceptualized as independent variables. When conducting scientific experiments, this approach, while not optimal, may be required to achieve interpretable outcomes.

In real-world practice, there are interactions between sex and gender, which produce observable health outcomes. For example, the genetic complement and resulting gene expression are influenced by biology, environment, and gendered behaviors. Much of the research regarding sports-related injuries concerned those sustained by men. With the advent of Title IX, more women began participating in competitive sports at all levels. This led to an increasing recognition of differing incidence of sports injuries between women and men, and many of these are a result of sex-based differences in risk factors, including the impact of sex hormones and differing anatomic alignment and neuromuscular control.

Sex and Gender from Cell to Society

Sex and gender matter for health and illness from the cell to society. Every cell has a sex, and emerging knowledge indicates that sex chromosomes continue to function in all cells throughout the lifespan. Consider the case of lung cancer and smoking: at a cellular level, DNA repair capacity is lower in female lung cancer patients. ¹⁶ At the physiologic level, men have larger lung capacity than women. Medications may have different consequences in men and women. In Phase 2 and Phase 3 published clinical trials, Erlotinib hydrochloride (Tarceva^®; OSI Pharmaceuticals, Northbrook, IL), a targeted lung cancer therapy, was shown to have less responsiveness in men. ¹⁷

If we consider sex differences on a societal level, U.S. women are more likely to be diagnosed with adenocarcinoma. Lung cancer is the primary cause of cancer mortality for both men and women, although the rate is higher among men. Women have a higher rate of lung cancer from exposure to second-hand smoke. When we factor in race, lung cancer is the primary cause of cancer mortality in all groups of women, except among Hispanic women, where it is breast cancer. ¹⁸ Of all groups, black males have the highest rates of lung cancer mortality. ¹⁹ Socioeconomic factors are also relevant in smoking; it is more common among those of lower socioeconomic status. ²⁰

On a behavioral level, smoking cessation is more difficult for women ²¹ and physicians have been shown to be less likely to recommend smoking cessation to women. ²² While physicians' lack of recommendations about smoking cessation exhibits a gendered pattern, the challenge of smoking cessation among women is likely to be related to both physiological and gender factors. Gendered factors may be relevant in gene expression, in addiction, and in therapeutic efficacy. The case of lung cancer and smoking shows the spectrum of sex differences, beginning at the cellular level up to and including the societal level where we can readily identify health disparities. For researchers and practitioners, sex and gender are relevant in all domains and at all levels, from basic science to public health.

Using a sex and gender lens, it is clear that there are other ways in which existing scientific knowledge has a gender bias. Not only have most clinical research subjects been white males, but even in animal studies, most laboratory animals have been male. Researchers have rarely specified whether the cell lines they used were male or female. In an effort to remedy the problem of bias in laboratory animal research, the NIH has stated that future federally funded studies must include cells and animals of both sexes if a health problem occurs in both sexes. ^23,24 Moving forward, using a sex and gender lens will lead us to reconsider disease classifications that have been created based on male bodies.

Physicians already use a gender lens in their work, but they do so implicitly. They use a gender lens when they erroneously assume men are more susceptible to cardiovascular disease and misdiagnose women as suffering from stress rather than coronary disease. Similarly, physicians use a gender lens when they assume that only women suffer from osteoporosis and fail to diagnose men with this condition. Applying a sex and gender lens correctly means that physicians and scientists will consider sex and gender evidence explicitly and correctly in their work.

We have generated a general model for understanding how sex and gender matter from cell to society (Fig. 1). Patients engage in gendered behaviors, which have an impact directly on the body and also on gene expression, which influences cells, hormones, and organs. However, the body itself can influence patients' actions in gendered ways. Some of patients' gendered behaviors such as risk taking behaviors, environmental exposures, or exposures to violence will result in disease. In terms of disease, there are differences in rates of illness, disease processes, and symptoms between men and women. When physicians make gendered assumptions about patients and recognize symptoms of illness in one sex and not another, or when they make different treatment decisions based on sex and gender, they engage in gendered behaviors that contribute to health disparities at a societal level. When medications are not adequately tested in both sexes and have differences in pharmacodynamics and pharmacokinetics, it contributes to health disparities. Health disparities observed at the societal level are exacerbated by disparities in the health system such as access to care or equipment that is designed for men's body size, but is also used for women.

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FIG. 1.

Sex and gender from cell to society.

The Sex and Gender Medical Education Summit

During October 18–19, 2015, the first Sex and Gender Medical Education Summit was convened at the Mayo Clinic in Rochester, MN, to create a roadmap for integrating foundational sex and gender knowledge into medical education. ²⁵ Both U.S. and international leaders in SGBM presented information about how sex and gender knowledge has been successfully and broadly integrated into medical curricula. Medical curricula leaders from 111 U.S. and international medical schools attended the Summit, as did representatives from professional, student, nonprofit organizations, and government agencies. Others from the United States and abroad participated via webcast. The Summit proceedings are available at: www.sgbmeducationsummit.org

Notably, some of our European colleagues shared their great progress in this arena such as Charité Hospital in Germany where faculty developed and institutionalized training modules and a literature database in SGBM, ²⁶ while the Karolinska Institute in Sweden developed a broad array of interprofessional teaching materials and resources. ²⁷ The Institute of Gender and Health in Canada has well established online webinars, modules, and a casebook, ²⁸ and the University of Toronto developed student seminars and a core course in SGBM.

In the United States, a number of institutions have begun to develop sex and gender course materials. Texas Tech University Health Sciences Center has a peer reviewed slide library, online interactive modules, and they have integrated sex and gender into clinical simulation teaching. ²⁹ Both the Mayo Medical School and Texas A&M Health Science Center College of Medicine pilot tested Texas Tech's modules, receiving positive responses from students. Other medical schools that have made substantive progress in integrating sex and gender into medical education include the David Geffen School of Medicine at the University of California in Los Angeles and Drexel University College of Medicine.

Many examples of how to integrate SGBM into medical curricula were presented at the Summit. Case materials can be adapted to reflect a sex and gender lens. Educational modules that use a sex and gender lens can be integrated into existing curricula. However, a more comprehensive approach would begin by assessing the existing content of medical curricula and identifying gaps and opportunities to integrate sex and gender content throughout the curriculum. Faculty who are leaders in SGBM should be involved in the curricular change process. Faculty allies can form a working group to advocate for SGBM and mentor students. Programs or offices established to lead SGBM initiatives were found to be helpful.

Medical schools that were successful found that it was important to involve all stakeholders. SGBM content was more effective with learners when it was relevant to them, such as linking curricula to experiential learning and research. It was important to support faculty by providing them with educational resources. Other factors that led to success and the challenges encountered are discussed in the Summit's proceedings. Discussions among Summit participants indicated support for incorporating this content throughout medical school curricula rather than establishing separate modules or courses.

There are now many resources available for researchers and educators about SGBM. A foundational text in SGBM, Principles of Gender-Specific Medicine, was first published in 2003 and is now available in a second edition. ³⁰ For practicing clinicians, modules are available from the NIH Office of Research on Women's Health (ORWH), as well as Texas Tech University Health Sciences Center. Practitioners who complete at least 10 hours of approved SGBM modules are eligible for inclusion in a National Sex and Gender Based Medicine Physician Registry, which is coordinated through the Sex and Gender Women's Health Collaborative. ³¹ A full listing of resources is available in the Summit proceedings.

There are plans to continue the work of the Summit. This includes assessing the integration of sex- and gender-based knowledge into medical curricula, publications of findings, development of student competencies, and convening an interprofessional sex- and gender-based health summit.

Moving from Women's Health to Sex and Gender Specific Women's Health

Women's health and gender scholars have created a substantive scientific foundation for understanding both sex and gender as they relate to a person's health. Unfortunately, this has not been incorporated comprehensively into medical education. Consequently, important research findings are not being translated into medical practice.

We propose the adoption of a broader framework that will enable us to integrate existing women's health knowledge with existing knowledge about men's health. From a scientific perspective, this will enhance our understanding of disease processes. Using a sex and gender lens will enable researchers to conduct valid research and enable educators to integrate knowledge about both men and women into medical education. As learners begin to think more critically using a sex and gender lens, they will be able to consider how and the extent to which scientific knowledge applies to the specific patient before them. This is a critical aspect of patient-centered care. A sex and gender lens is the path for changing medical practice and improving the health of all patients.