Background: Besides the number of publications, the number of citations is another key metric often used to compare researchers with each other. While women researchers tend to have fewer publications than their men colleagues, the data is scarce for the number of citations. We aimed to determine whether there is a gender gap in citations.

Methods: We used Web of Science to retrieve the number of citations per year for all research articles and reviews published between January 2015 and December 2019 in fourteen high-impact general medical journals (impact factor > 5). We used Gender API to identify the gender of the first/last authors. We compared the results by gender using multivariable negative binomial regressions (adjusting for intra-cluster correlations within journals).

Results: The gender of the first/last author was determined for 13,218/13,350 (99%) and 11,894/12,026 (99%) articles, respectively. The proportion of women among first/last authors was 40% and 29%, respectively. The median number of citations per year was 5 (IQR = 11.3) for women and 6.8 (IQR = 17.8) for men for first authors (IRR = 1.5 [95% CI = 1.3-1.8], p value < 0.001), and 6 (IQR = 12.4) and 7.5 (IQR = 17.4) for last authors (IRR = 1.3 [95% CI = 1.2-1.5], p value < 0.001). Articles whose first and last authors were women were the least cited and those whose first and last authors were men were the most cited.

Conclusion: In this cross-sectional study, we found that articles authored by women were cited less often than those authored by men. Further studies are needed to explore the reasons for these gender differences in article citations.