The Policy of Co-First Authorship and Co-Senior Authorship in Radiology Journals

Increasingly, medical journals are recognizing "equally credited authors" (ECA) in the primary and senior authorship of articles. The aim of this study was to assess the policies of co-first authorship, co-senior authorship, and designation of a corresponding author in the radiology literature.

We identified 29 radiology journals based on impact factor ranking. Journal offices were contacted by phone and e-mail to ascertain their practices on first and senior authorship ECA designations. We surveyed the March, June, and December 2018 issues of each journal (when available) to assess the utilization of the co-designations in articles.

Twenty-five of 29 journals responded to our survey (response rate: 86.2%). Of 25 journals, 20 (80%) allowed co-first authorship. Among these, 4 of 25 journals (16%) allowed more than two co-first authors. Among the 25 responses, 14 journals (56%) allowed co-senior authorship. Among the 24 journals who responded to this specific question, 23 (96%) approved designation of a corresponding author, different from the first or senior author. The review of March, June, December 2018 editions found co-first authorship and co-senior authorship ECA rates of 8.6% (range 0.0%-22.7%) and 1.8% (range 0.0%-13.3%), respectively. A corresponding author other than first or senior author was noted in 13.3% (range 0.0%-34.7%).

There has been widespread acceptance of the concept of ECA in the policies of the top cited imaging journals particularly for first authors (80%). However, the utilization of these designations is uncommon for first authorship (8.6%) and rare (1.8%) for senior authorship based on our 2018 sampling.