Related Experiment Video
Updated: Dec 28, 2025

Global and Current Research Trends of Single-Cell Sequencing in Cancer: A Bibliometric and Visualization Study
Published on: April 18, 2025
Increasing number of authors in Cochrane reviews
Sengül Gülen1, Siv Fonnes1, Kristoffer Andresen1,2
1Center for Perioperative Optimization, Department of Surgery, Herlev and Gentofte Hospital, University of Copenhagen, Herlev, Denmark.
Objective:
To investigate authorship trends in Cochrane reviews from 1996 to 2018, and to examine if the authorship criteria from the International Committee of Medical Journal Editors (ICMJE) were met for Cochrane reviews with more than 15 authors based on the text in the section "Contributions of authors."
Methods:
The median number of authors per review was calculated, and authorship trends within each editorial group were analyzed. The section "Contributions of authors" was assessed about the first and second authorship criteria from the ICMJE for reviews with more than 15 authors.
Results:
A total of 7447 Cochrane reviews were studied based on data from the Cochrane Database of Systematic Reviews. The median number of authors per Cochrane review was 3 in 1996 (IQR 2.5-3, range 2-3), 4 in 2007 (IQR 3-5, range 1-13), and 5 in 2018 (IQR 4-7, range 2-22). Within each editorial group, the total number of authors either increased (26/55, 47%) or was unchanged (29/55, 53%). Based on the text in "Contributions of authors," 59% (16/27) of the reviews with more than 15 authors had authors that did not fulfil the ICMJE authorship criteria. However, the text in "Contributions of authors" was often difficult to interpret.
Conclusions:
The number of authors per Cochrane review gradually increased from 1996 to 2018. The ICMJE authorship criteria were probably not met by all authors in more than half of the reviews with more than 15 authors.
Related Concept Videos
Cofactors and Coenzymes
Cofactors and Coenzymes
Cofactors can be metallic ions or organic molecules called coenzymes. These types of helper...
Correlation and Causation
Correlation versus Causation
If the dependent variable increases or decreases when the independent variable increases, there is a positive or negative...
Cohesion
On a...
The Scientific Method
Generally, predictions are tested using carefully-designed experiments. Based on the outcome of these...
Hardy-Weinberg Principle

