How many authors are (too) many? A retrospective, descriptive analysis of authorship in biomedical publications

Publishing in academic journals is primary to disseminate research findings, with authorship reflecting a scientist's contribution, yielding academic recognition, and carrying significant financial implications. Author numbers per article have consistently risen in recent decades, as demonstrated in various journals and fields. This study is a comprehensive analysis of authorship trends in biomedical papers from the NCBI PubMed database between 2000 and 2020, utilizing the Entrez Direct (EDirect) E-utilities to retrieve bibliometric data from a dataset of 17,015,001 articles. For all publication types, the mean author number per publication significantly increased over the last two decades from 3.99 to 6.25 (+ 57%, p < 0.0001) following a linear trend (r(2) = 0.99) with an average relative increase of 2.28% per year. This increase was highest for clinical trials (+ 5.67 authors per publication, + 97%), the smallest for case reports (+ 1.01 authors, + 24%). The proportion of single/solo authorships dropped by a factor of about 3 from 17.03% in 2000 to 5.69% in 2020. The percentage of eleven or more authors per publication increased similar to sevenfold, similar to 11-fold and similar to 12-fold for reviews, editorials, and systematic reviews, respectively. Confirming prior findings, this study highlights the escalating authorship in biomedical publications. Given potential unethical practices, preserving authorship as a trustable indicator of scientific performance is critical. Understanding and curbing questionable authorship practices and inflation are imperative, as discussed through relevant literature to tackle this issue.