In an analysis of 35 million citations, PubMed found that 99.9% of them had fewer than 99 authors but 67 had between 900 and 999 and another 571 had over 1,000 authors. This aligns with a study by George Choueiry in Quantifying Health . His sample size was smaller—101,580 fulltext articles published between 2016 and 2021. The median research paper had 6 authors, with 90% of papers having between 1 and 15 authors. The median number of authors of a research paper increased, from 3 to 6, in the past 20 years. The maximum number of authors he found was 2,902.
PubMed’s approach to multiple authors
According to PubMed in its Technical Bulletin announcement , when viewing search results in the Summary display format, author lists are now truncated after 1,200 characters followed by an ellipsis (…) and a link to "See abstract for full author list". In practice, this change applies to citations with approximately 100 or more authors, or around .01% of citations in the PubMed database.
This change to the search results display is based on feedback submitted to the NLM Help Desk that citations with hundreds or thousands of authors affect the usability of the search results. Truncating these comparatively long author lists is intended to make the search results easier to navigate when using the Summary display format.
Truncated author lists now appear in the Summary display format used for lists of citations on the PubMed website, e.g., in search results, Clipboard, and Similar Articles. There is no change to the mobile display, which already truncated author lists to conserve space on small screens. There are no changes to author lists in the cite, save, and email features in any format.
Searchers can continue to view complete author lists for all citations on the Abstract page or using the Abstract display format for search results. If you would like to always display search results using Abstract format, please register for a free My NCBI account and follow the instructions for customizing the PubMed search results display.
NLM notes that the policy related to author names in PubMed/MEDLINE has changed over time. See Number of Authors per MEDLINE®/PubMed® Citation for more information about the number of authors indexed on MEDLINE/PubMed citations over the years.