Challenging gender bias in research

The standard use of the caucasian male as a universal subject in medical research is no longer ethically, scientifically, and socially plausible, say Olaya Madrid Pascual and colleagues

We are a gender equity research team whose latest project[1] investigated how many of the Cochrane reviews published in 2018 reported and analysed evidence on sex and gender, and how this correlated with the gender of the authors. Cochrane systematic reviews are a cornerstone for treatment recommendations, nevertheless, we found that sex and gender is scarcely considered in their reports. 

While the value of investigating this is clear to us, several of the reactions to our research has made it apparent that some members of the scientific community find our motives for undertaking this work an unsolvable mystery. 

Some of the common responses we’ve faced could be summarised as follows: is reporting by sex and gender really necessary? Why would you expect sex and gender to affect the final results on an intervention? And what about your own bias, as a group of only women?

We think that these kinds of questions largely miss the point. Not only do they show a worrying lack of awareness about the broad body of evidence that has shown how sex based differences can affect patients’ clinical presentations and responses to treatments,[2,3,4] they’ve also failed in the attempt to shake the foundations of our work. Indeed, if anything, they’ve only encouraged us to carry on and expand our work, revealing how it is more relevant than ever. 

We would ourselves miss the point if we simply tried to answer those questions. The real issue here is not whether researching the omission of sex and gender reporting in the scientific literature is “really necessary,” but whether the standard use of the caucasian male as a universal subject in medical research is still ethically, scientifically, and socially plausible. For too long, this is what the medical and scientific establishment has always assumed, but this convention has legitimised itself for centuries only by pure repetition. Conversely, for some reason, what comes from outside this echo chamber has the burden of proof.

Some people will challenge whether we have gathered enough evidence to show that medical interventions working equally well in men and women is the premise of an echo chamber. Yet are there reasons to think that the caucasian male is representative of all human beings and should therefore be used as the default participant from which all effects are measured?

We appreciate that our understanding of the world is influenced by our own perspective and that there is no possible “view from nowhere.” We all are shaped by our sex and gender, ethnicity, personal history, or socioeconomic situation. Yet this should not be used as an excuse to discount a systematic error in the planning, data collection, analysis, and publication of research (otherwise known as “bias”). 

Those men who have raised concerns about our potential bias as a research group of only women need to understand that they are, at least, as influenced by their contexts as we are. They were assuming, once again, that manhood is the standard upon which everything needs to be compared. To our knowledge, research from groups of only men that present data about only men do not receive the same accusations of bias. 

Women researchers, as part of a scientific community that is heavily influenced by the wider environment (and the systems of power within it), can also be blinkered by the same biases as our male counterparts and overlook sex and gender in research. Yet at the same time, as members of the affected party so to speak, we’d argue that we might be more sensitive to gender bias in research and finding ways to counteract it.[5] We think that this outlook can help to build a richer and more inclusive body of science and scientific community, with the ultimate aim of representing and benefitting our diverse society.  

Olaya Madrid Pascual is an internal medicine physician from Spain. She lives in Zürich and works at the medical practice Kalkbreite. 

Emilia Roy Vallejo is an internal medicine physician and PhD candidate at the Internal Medicine Unit, Hospital Universitario de La Princesa, Madrid

Montserrat León García is a pharmacist and PhD candidate in public health at Universitat Autónoma de Barcelona.

They write this reflection on behalf of Research for Gender Equity, a collaborative research group that focuses on the underrepresentation of women in science.

Competing interests: None declared.

Acknowledgement: We would like to deeply thank and acknowledge the work done by the following women, whose ideas and reflections have contributed profoundly to this text: Montoya-Martínez, María; González-Barral, María; Cuadrado-Conde, Ana; Calderón-Larrañaga, Sara; Antequera-Martín, Alba. 


  1. Antequera A, León M, Calderón S, et al. Sex and gender reporting and analysis in Cochrane reviews: a cross-sectional methods study. Preliminary results. BMJ Evidence-Based Medicine 2019;24:A18-A19.
  2. Dey S, Flather M, Devlin G, Brieger D, et al. Sex-related differences in the presentation, treatment and outcomes among patients with acute coronary syndromes: the Global Registry of Acute Coronary Events. Heart 2008;95(1):20-26.
  3. U.S. Government Accountability Office, GAO-01-286R. Drug safety: Most drugs withdrawn in recent years had greater health risks for women, 2001. Available at:
  4. Pinn V. Sex and Gender Factors in Medical Studies. JAMA 2003;289(4):397.
  5. Nielsen M, Andersen J, Schiebinger L, Schneider J. One and a half million medical papers reveal a link between author gender and attention to gender and sex analysis. Nature Human Behaviour 2017;1(11):791-796.