Sex bias persists in surgical research: A 5-year follow-up study

Abstract

Background: Federal initiatives have recently addressed the sex bias that exists in biomedical and clinical research. However, improvement to the inclusion of sex as a biological variable remains unknown. Methods: We performed a 5-year follow-up study of all clinical and biomedical research articles published in 5 surgical journals from January 1, 2017, through December 31, 2018. Human, animal, and cell subjects were analyzed for study/subject type, sex of participants, sex matching, and sex-based data reporting, analysis, and discussion. Results: Comparing 2017 to 2018 with 2011 to 2012, slightly more articles reported the sex of the human studied (87% vs 83%; P ¼ .001). Inclusion of both sexes remained high (94% vs 95%; P ¼ .22), but sex-based data reporting (36% vs 38%; P ¼ .17), analysis (35% vs 33%; P ¼ .39), and discussion of results (10% vs 23%; P < .0001) remained unchanged or worsened. Regarding animal research, the number of articles that stated the sex studied remained unchanged (79% vs 78%; P ¼ .67); if stated, slightly more included both sexes (7% vs 3%; P ¼ .002). Regarding cell research, fewer articles reported the sex of the cells studied (5% vs 24%; P ¼ .0001); if stated, more articles included both sexes, but the difference did not reach statistical significance (25% vs 7%; P ¼ .34). Sex matching remained poor with only 50% of human, 4% of animal, and 9% of cell studies matching the inclusion of both sexes by at least 50%. Conclusion: Sex bias persists in surgical research. The majority of articles failed to report, analyze, or discuss results based on sex, which will negatively affect clinical translatability and outcomes of evidence-based medicine.

Minimal influence of estrous cycle on studies of female mouse behaviors

“…Experimental designs with sex bias have been recognized as an issue in both basic and translational research ( Kong et al, 2016 ; Stephenson et al, 2018 ; Villavisanis et al, 2018 ; Xiao et al, 2018 ; Coiro and Pollak, 2019 ; Plevkova et al, 2020 ; Flynn et al, 2021 ; Mercel et al, 2021 ; Mondini Trissino da Lodi et al, 2022 ; Spitschan et al, 2022 ). Even in clinical studies, the number of female participants is underrepresented substantially ( Mansukhani et al, 2016 ; Villavisanis et al, 2018 ; Feldman et al, 2019 ; Karp and Reavey, 2019 ; Burra et al, 2022 ; Mondini Trissino da Lodi et al, 2022 ).…”

Comparative Outcomes of Groin Hernia Repair by Sex Among Medicare Beneficiaries

“…W hile much has been written about the importance of including sex as a biological variable in research, most studies fail to do so. 1,2 The lack of sex-based analyses or stratification often leads to worse outcomes for patients due to differences related to biology (eg, anatomy, hormones) or differential experience of care in the healthcare system (eg, sexism leading to biased care). [3][4][5] Nowhere is this more true than in the example of elective groin hernia repair.…”

The Female Groin Hernia

“…Despite policies encouraging the inclusion of both females and males in research, there remains a significant sex bias (favoring males) in research. 1 Unfortunately, this often results in worse outcomes among females. A commonly cited example is that of heart disease which has traditionally been considered a male-centric disease.…”

“…Historically, females were excluded due to concerns about anatomical differences, potential for child-bearing, and even the potential risk that “female hormones” might influence the study results. Despite policies encouraging the inclusion of both females and males in research, there remains a significant sex bias (favoring males) in research 1 . Unfortunately, this often results in worse outcomes among females.…”