The medical implications of sex versus gender

Editor's Note: The author is a physician who recently tried to submit a letter to the editor for publication to three major US medical journals on the issue of gender v sex and clinical applications in the practice of medicine and it was rejected by all three.
The gender definition and distinction from sex was actually made by the World Health Organization,  yet many doctors do not know this, bet the patients do.
If the medical profession cannot get this issue straight and use correct terminology then who can?


Over the past 20 years, there has been an increasing tendency to use the words "gender" and "sex" interchangeably.  It is important for physicians and the editorial staff of medical journals to recognize that these words are not synonymous and that incorrect or inconsistent use in patient interaction and risk stratification and treatment tools that include sex as a criterion could have adverse medical consequences.

Sex is an objective descriptor of the biological characteristics that differentiate males from females.  Sex is described by the nouns male and female.

Gender, however, is, by definition, a subjective state of mind, a psychosocial construct frequently used to designate discordance with sex; thus the commonly heard term "gender identity."  Historically, gender has been a grammatical taxonomic term in Indo-European languages to describe nouns by the adjectives masculine, feminine, and neuter.  The word gender was never used in reference to persons until recently.

Non-historically conforming usage of the word gender began in 1955, when sexologist John Money used it to describe one's state of mind and behavior, encompassing self-identity, societal expectations, and assumed sexual roles in society.

In the 1970s and 1980s, the word gender began to appear in feminist literature in reference to the social construct of masculinity and femininity.  The word sex continued to be used to designate biological differences between males and females.  But this changed in the 1990s, when Supreme Court justice Ruth Bader Ginsburg began using gender synonymously with sex in reference to persons.  It was she who popularized the term "gender discrimination."

In 1993, the FDA began to use gender in place of sex.  This misuse in terminology began to appear in the medical literature, as reflected in titles such as "Influence of gender on ICD implantation for primary and secondary prevention of sudden cardiac death," in Europace in 2007 (1).

In 2011, the FDA reversed its previous substitution of gender for sex and began to use sex as a biological classification and gender as a psycho-social classification, "a person's self representation as male or female, or how that person is responded to by social institutions based on the individual's gender presentation."  This was consistent with the following distinction made by the World Health Organization in the same year: "Sex refers to the biological and physiological characteristics that define men and women. Gender refers to the socially constructed roles, behaviors, activities, and attributes that a given society considers appropriate for men and women."

But in spite of this clarification, the substitution of gender for sex has persisted, as reflected in the titles of articles appearing in the medical literature, such as "Impact of gender on the prognosis of patients with nonvalvular atrial fibrillation," in The American Journal of Cardiology in 2014 (2), and "Gender differences in anticoagulation and stroke outcomes in atrial fibrillation," in Circulation in 2015 (3).  Given that gender is, by definition, a psychosocial construct and not a biological reality, it is important for the medical literature to reflect that definition and for physicians to use correct terminology in documentation, as failure to correctly distinguish the differences between a state of mind and a biological reality could result in serious untoward consequences in patient care.

The CHADS-VASC score, a conventional tool used to determine the risk of stroke in association with atrial fibrillation, uses sex as one criterion (4).  A failure to differentiate gender from sex could result in an overestimate, or underestimate, of the risk for stroke, leading to a treatment decision in favor of, or against, anticoagulation.  The ramifications of this could be serious either way, and legal defense in the event of litigation could be compromised.

While it is appropriate to document gender in the psychiatric and social history of a medical record, the objective segments of medical documentation should, in compliance with the traditional SOAP format, indicate sex, and treatment decisions that differ for the sexes should be based upon sex and not gender.

Because most patients with sex-gender discordance are aware of the difference between the words gender and sex, questionnaires should not request gender in lieu of sex, nor should physicians transpose the terms in conversation.

This distinction should also be appreciated and used by the editorial staff of medical journals to avoid publication of articles as mentioned above.


1. Davis, Tang, et al. Influence of gender on ICD implantation for primary and secondary prevention of sudden cardiac death. Europace. 2006; 8; 12:1054-2956

2. Inoui, Atarashi, et al. Impact of gender on the prognosis of patients with nonvalvular atrial fibrillation. The American Journal of Cardiology. 2014; 113; 6: 957-96

3. Kassim, Qin, et al. Gender differences in anticoagulation and stroke outcomes in atrial fibrillation. Circulation, 2015: Abstract

4. Cardiology CHADS2-VASc calculator for atrial fibrillation.