Abstract
Background: Women have continued to be underrepresented in cardiovascular (CV) research despite comprising 44.7% of all CVD burden, resulting in CV trial data based mainly on males. This study aims to temporally evaluate female enrollment and trial authorship demographics by sex, race, and age in CV trials published from 2016 to 2022.
Methods: MEDLINE was searched using a previously validated search strategy for CV trials of various types published in the Lancet, JAMA, and the New England Journal of Medicine from 2016 to March 10th, 2022. Participant and investigator demographics, types of interventions, clinical indication, and trial characteristics were compared with women’s enrollment.
Results: From 170 CV trials, including data from 927,467 participants, women’s enrollment increased significantly over time (8.3% between the year 2016 and March 10th, 2022, P = <0.001), and there were no differences in enrollment by type of funding (peer-reviewed vs industry funding). CV trials published in JAMA enrolled significantly more women (P = 0.04). Women’s enrollment differed significantly by trial indication, representing 27.0% of coronary artery disease (CAD), 37.4% of non-coronary/vascular, 29.8% of heart failure (HF), 36.9% of arrhythmia and 33.9% of other CV trials (P = 0.001). Women’s enrollment in CAD or HF trials was 18.3% and 13.5% lower than the percentage of women with the diseases in the population, respectively. Women’s enrollment varied by type of trial but did not differ significantly, representing 30.4% of pharmacological, 28.5% of procedural, 33.8% of device, and 30.6% of other CV trials (P = 0.49). Female first authors were significantly more likely to enroll more women than male first authors (P = 0.04), with a mean difference of 7.1%, and a non-significant difference between corresponding author sex and women’s enrollment (P = 0.11), with a mean difference of 4.0%. A positive correlation between women enrolled and mean age was found (Spearman’s r = 0.35, P = < 0.001). The lack of race-based participant data precluded further analysis.
Discussion: Women’s enrollment in CV trials has increased in the last five years but still does not reflect prevalence rates by disease population. Future CV trials should collect more diverse participant data and increase their enrollment to reflect the population.
