The average number of authors listed per publication has increased significantly in major radiology journals, according to a recent study published by Academic Radiology.

Neena Kapoor, MD, Brigham and Women’s Hospital, Harvard Medical School, and colleagues analyzed more than 680 research and review articles from Radiology, American Journal of Roentgenology (AJR), and European Radiology from 1980-2013. During that time, the number of authors per article jumped from 3.6 to 7.3.

“Despite multiple attempts to create and revise authorship guidelines for scientific literature, the perception of honorary authorship remains high in radiology,” Kapoor and colleagues wrote.

The research team also explores some possible explanations for why honorary authorship is so common, including the “drive for academic promotion” and “obligation or fear or to gain favor or repayment.”

Inexperienced authors may also be tipping the scales to help themselves: “Junior researchers may also give authorship to senior colleagues to give their research more clout and in the hopes that authorship inclusion may increase the chance of publication.”

From 2000-2013, the number of authors per article jumped from 6.0 to 8.1 for Radiology and 4.9 to 8.2 for European Radiology. For AJR, however, the number remained the same: 5.7 authors per article.

The authors added that the AJR is also the only journal of the three that explicitly limits the number of authors before additional documentation is required.

“The stabilization of authorship count in AJR suggests that this approach may be useful in curbing authorship inflation,” Kapoor and colleagues wrote. “This policy motivation is also consistent with broader evidence that the fulfillment of [International Committee of Medical Journal Editors] authorship criteria has been shown to decrease as the number of authors increase. This is not to suggest that journals should have a firm cutoff for the number of authors per article, but rather that requiring greater justification for a large number of coauthors could prove useful in curtailing authorship inflation.”

The team concluded by saying this is a legitimate problem for numerous reasons, including the impact it could have on both academia and the future of patient care.

“Authorship not only implies prestige and credit but also accountability for the work that has been published,” Kapoor and colleagues wrote. “It has been argued that each author must be able to take public responsibility for the contents of a manuscript. When accountability has been diluted, authors may be unwilling or unable to ensure the accuracy of the entire manuscript.”