Increasing author counts in neurosurgical journals from 1980 to 2020

Scientific productivity, as assessed by publication volume, is a common metric by which the academic neurosurgical field assesses its members. The number of authors per peer-reviewed article has been observed to increase over time across a broad range of medical specialties. This study provides an update to this trend in the neurosurgical literature.

All publications from January 1, 1980, to April 30, 2020, were queried from four neurosurgical journals: Neurosurgery, Journal of Neurosurgery (JNS), JNS: Pediatrics, and JNS: Spine. Publication information was acquired from the National Center for Biotechnology Information Entrez database and reconciled with the Scopus database. Publication type was limited to articles and excluded editorials, letters, and reviews. The number of authors and affiliation counts were determined based on structured abstract fields provided in the two databases.

Between January 1, 1980, and April 30, 2020, the overall increase in author count for the four neurosurgical journals was 0.12 to 0.18 authors per year (p < 0.001). For Neurosurgery, the mean (SD) author count increased from 2.81 (1.4) in 1980-1985 to 7.97 (4.92) in 2016-2020 (p < 0.001). For the JNS, the mean (SD) author count increased from 2.82 (1.04) in 1980-1985 to 7.6 (3.65) in 2016-2020 (p < 0.001). The percentage of articles with more than 10 authors increased from 0.2% to 22.3% in Neurosurgery and from 1.9% to 17.5% in JNS. Only 28% of the author count variation was explained by an increasing number of institutional or departmental affiliations.

Author counts for peer-reviewed articles in neurosurgical academic journals have increased significantly during the past 4 decades, with large increases in the numbers of articles with more than 10 authors in the past 5 years. A total of 28% of the variation in this increase can be explained by an increase in multiinstitutional or multidepartmental studies.