Sex and gender are not synonymous. Sex, unless otherwise specified, relates to biology: the gametes, chromosomes, hormones, and reproductive organs. Gender relates to societal roles, behaviours, and expectations that vary with time and place, historically and geographically. These categories describe different attributes that must be considered depending on the purpose they are intended for. The World Health Organization states, “Gender is used to describe the characteristics of women and men that are socially constructed, while sex refers to those that are biologically determined.”

However, contemporary medical research and clinical practice often erroneously use sex and gender interchangeably. Furthermore, there are other categories, again with distinct purposes. UK law allows registered sex on a birth certificate to be changed when a gender recognition certificate has been issued. This certificate, of legal sex, requires a medical diagnosis and approval by a committee. Administrative sex categories such as those recorded in passports or NHS numbers can be changed from female to male, or vice versa, on request…

Bewley, S., McCartney, M., Meads, C., & Rogers, A. (2021). Sex, gender, and medical data. BMJ.

The COVID-19 pandemic has brought to the fore the implications of sex and gender differences to human health and well-being. Evidence to date indicates that men are at higher risk of severe disease and death than women, while women seem more likely to suffer from long-term COVID-19, and experience negative social and economic impacts. Biological sex as well as gender roles and behaviours can affect exposure to the virus and influence the prevalence of pre-existing conditions or harmful habits. Incorporating sex and gender considerations into clinical research on COVID-19 from the outset would help to identify differential patterns of risk, underlying reasons for disparate outcomes and to develop interventions to effectively respond to the various needs of women and men. Given the growing recognition of the relevance of sex and gender in the COVID-19 pandemic, the rationale for this analysis was to examine whether these dimensions are taken into account in clinical research on COVID-19.

We carried out a systematic review of COVID-19 research to examine how sex and gender are integrated and reported using the Sex and Gender Equity in Research (SAGER) guidelines recommendations as analytical categories. A PubMed search for interventional and observational trials on COVID-19, published from 1 December 2019 to 12 September 2020 resulted in 2066 studies…

Palmer-Ross, A., Ovseiko, P. V., & Heidari, S. (2021). Inadequate reporting of COVID-19 clinical studies: a renewed rationale for the Sex and Gender Equity in Research (SAGER) guidelines. BMJ Global Health, 6(4), e004997.

The number of COVID-19 cases appears to be comparable between men and women, but the severity of disease and death is two times greater for men than for women. History, including the 1918 influenza pandemic, warned us that male biases in COVID-19 could occur. In this Viewpoint, we focus on biological explanations, with a forward look at why clinicians and biomedical researchers should consider sex as a biological variable that will affect treatment outcomes for COVID-19. There is a long history of not analyzing or reporting differences between women and men in the prophylactic or therapeutic treatment of infectious diseases. We seek to reverse this trend and call on investigators developing and testing therapeutic and prophylactic approaches for COVID-19 to design studies that are inclusive of male versus female differences in drug responses, immunotherapies, vaccines, and nonpharmacological interventions.

Bischof E, Wolfe J, Klein SL. Clinical trials for COVID-19 should include sex as a variable. Journal of Clinical Investigation. 2020;130(7):3350-3352. doi:10.1172/jci139306