Neuro-oncology authorship trends in gender since 1944: a systematic review of 14,020 articles from five top-tier academic journals

Objective: This study was performed to compare authorship trends, by gender, in the neurosurgical oncology literature.

Methods: Complete author listings for neurosurgical oncology articles published between 1944 and 2021 in five top neuro-oncology journals were extracted from the PubMed database and journal websites on December 2, 2021. Author gender was characterized with the web application programming interface (API) genderize.io. The statistical significance (p < 0.05) of time-, journal-, and gender-based differences was determined by independent-samples t-test, chi-square test, and/or Fisher's exact test.

Results: A total of 14,020 articles were written by 67,115 unique authors occupying 97,418 authorship spots. The gender for 80,030 authorship positions (82.2%) was successfully characterized. Male authors were significantly more likely than the female authors to have a first-author publication, have a last-author publication, and have authored multiple articles within the data set. Among authors who published in multiple different years (n = 11,532), women had a shorter time window of publishing (5.46 vs 6.75 years between first and last publication: mean difference [MD] 1.28 [95% CI 1.06-1.50] years, p < 0.001). During this window, however, they were slightly more productive than the men, based on the mean number of publications per year (1.06 vs 1.01 articles: MD 0.05 [95% CI 0.02-0.09] articles, p = 0.002). The percentage of female authors on each neuro-oncology research team has increased by 3.3% (95% CI 2.6%-3.9%) per decade to a mean of 26.5% in the 2020s. Having a female last author was positively associated with having a female first author (OR 2.57 [95% CI 2.29-2.89]) and a higher proportion of women on the research team overall. The percentages of female first and last authors increased at significantly higher rates in medically oriented journals than in surgically oriented journals (first authors: 0.72% [95% CI 0.58%-0.87%] vs 0.36% [95% CI 0.30%-0.42%] per year, p < 0.001; and last authors: 0.50% [95% CI 0.38%-0.62%] vs -0.03% [95% CI -0.10% to 0.05%] per year, p < 0.001).

Conclusions: Female authorship in top neuro-oncology journals has increased since the 1940s, with female-led teams showing greater gender diversity. However, female researchers lag behind their male counterparts in quantity of published research and are less likely to hold first or last authorship positions. This difference is more pronounced in the three neurosurgical oncology journals than in the two medical neuro-oncology journals, which may reflect the relatively low female representation in neurosurgery relative to medical oncology. Collectively, these trends have meaningful implications for career advancement, which is often dependent on academic productivity.