Gender Bias in Clinical Trial Enrollment: Female Authorship Matters.

BACKGROUND: Despite initiatives to promote equal enrollment of human subjects in clinical trials, females continue to be underrepresented. The goal of this work is to determine if female enrollment in human clinical trials published in 3 high-impact journals from 2015 to 2019 is correlated with gender of first and/or senior authors. METHODS: Clinical trials published in the Journal of the American Medical Association (JAMA), The Lancet, and the New England Journal of Medicine (NEJM) from January 1, 2015, to December 31, 2019, were reviewed. Trials were excluded for ongoing enrollment, sex-specific disease research, or author name without gender assignment. One-sample χ2 pairwise comparisons and two-tailed proportion tests on the proportion of females between gender author pairings were done overall and for each subset analysis. RESULTS: In total, 1,427 articles enrolled a total of 2,104,509 females and 2,616,981 males (44.6% vs. 55.4%, P ≤ 0.0001) in clinical trials. Overall, more females were enrolled if both first and senior authors were female (51.7% vs. 48.3%, P ≤ 0.0001). Proportion of females enrolled decreased with the following first and senior author pairings: female-male (48.9%), male-female (48.6%), and male-male (40.5%, P ≤ 0.0001 compared to female-female authorship). Greater female enrollment in clinical trials with female-female compared to male-male authorship persisted in subset analyses by funding source, phase, randomization for study participants, drug and/or device trial, and geographic location. Female enrollment was higher in 3 surgical specialties: neurosurgery (all authors: 52%, P ≤ 0.01), ophthalmology (all authors: 53.6%, P ≤ 0.0001), and surgery (all authors: 54.4%, P ≤ 0.0001). The majority of surgical specialties did not publish trials with female-female authorship but when stratifying by author gender pairing, surgical oncology had the highest female enrollment with female-female authorship (98.4%, P ≤ 0.0001). CONCLUSIONS: Female authorship of clinical trial publications, specifically having both first and senior authors as female, was correlated with higher female enrollment in clinical trials when compared to male authorship and endured with multiple subset analyses.

The Persistence of Sex Bias in High-Impact Clinical Research.

INTRODUCTION: Sex bias is present in clinical research resulting in disparities in the treatment of women. Our objective was to identify the prevalence of sex inclusiveness of participants in human clinical trials after the passage of National Institutes of Health (NIH) and United States Congress policies in 2015 and 2016 to increase female enrollment in clinical research. METHODS: We performed an observational analysis of data from registered clinical trials published in three high-impact biomedical journals from January 1, 2015 to December 31, 2019. RESULTS: One thousand four hundred and forty two manuscripts with 4,765,783 human subjects were included for analysis. Significantly more males (56%) than females (44%) were included in all three journals (P < 0.0001). Sex matching ≥ 80% was found in 24.6% of publications. Industry funded 43.7% of all studies enrolling significantly more males than females (60.8% versus 39.2%, P < 0.0001). NIH funded 10.2% of studies enrolling significantly more females than males (52.7% versus 47.3%, P < 0.0001). North America and Europe contributed 82.6% of the studies with each enrolling significantly more males than females (P < 0.0001). The United States was the country contributing the most studies (36.1%), enrolling significantly more males than females (55.5% versus 45.5%, P < 0.0001). Cardiovascular disease was the subject area of the most manuscripts among medical specialties (19%), enrolling significantly more males than females (64.9% versus 35.1%, P < 0.0001). Studies analyzed by clinical trial phase, type, trial, and allocation enrolled significantly more males than females (P < 0.0001). CONCLUSIONS: Sex bias remains prevalent in human clinical research trials. Improvements have been made in NIH-funded clinical trials; however, this constitutes a small percentage of overall studies.

Development of Optimized Tissue-Factor-Targeted Peptide Amphiphile Nanofibers to Slow Noncompressible Torso Hemorrhage.

Noncompressible torso hemorrhage accounts for a significant portion of preventable trauma deaths. We report here on the development of injectable, targeted supramolecular nanotherapeutics based on peptide amphiphile (PA) molecules that are designed to target tissue factor (TF) and, therefore, selectively localize to sites of injury to slow hemorrhage. Eight TF-targeting sequences were identified, synthesized into PA molecules, coassembled with nontargeted backbone PA at various weight percentages, and characterized via circular dichroism spectroscopy, transmission electron microscopy, and X-ray scattering. Following intravenous injection in a rat liver hemorrhage model, two of these PA nanofiber coassemblies exhibited the most specific localization to the site of injury compared to controls (p < 0.05), as quantified using immunofluorescence imaging of injured liver and uninjured organs. To determine if the nanofibers were targeting TF in vivo, a mouse saphenous vein laser injury model was performed and showed that TF-targeted nanofibers colocalized with fibrin, demonstrating increased levels of nanofiber at TF-rich sites. Thromboelastograms obtained using samples of heparinized rat whole blood containing TF demonstrated that no clots were formed in the absence of TF-targeted nanofibers. Lastly, both PA nanofiber coassemblies decreased blood loss in comparison to sham and backbone nanofiber controls by 35-59% (p < 0.05). These data demonstrate an optimal TF-targeted nanofiber that localizes selectively to sites of injury and TF exposure, and, interestingly, reduces blood loss. This research represents a promising initial phase in the development of a TF-targeted injectable therapeutic to reduce preventable deaths from hemorrhage.