Biomedical authors often call a reference “recent” — even when it is decades old, analysis shows

Authors in biomedical journals frequently describe cited evidence as “recent,” yet the actual age of the references behind these phrases has rarely been measured. 

To measure how recent the "recent" studies really are, researchers based in Spain analysed 1000 biomedical articles containing 20 predefined “recent” expressions directly linked to a citation. 

Their findings in the Christmas issue of The BMJ show that the citation lag ranged from 0 to 37 years, with a median of 4 years and a mean of 5.5 years.  

The most frequent lag was 1 year, yet almost one in five “recent” references (177, 18%) cited work that was at least 10 years old. Twenty-six citations had a lag of 20 years or longer, and four articles cited references that were at least 30 years old. 

Citation patterns varied across medical specialties. Critical care, infectious diseases, genetics, immunology, and radiology showed shorter median lags (around two years), while nephrology, veterinary medicine, and dentistry displayed substantially longer lags (ranging from 8.5 to 14 years).

Among expressions, “recent approach,” “recent discovery,” and “recent study” were linked to older references, whereas “recent publication” and “recent article” had much fresher citations.

Patterns were stable across world regions and gradually improved over time: articles published between 2020 and 2025 showed the shortest lags. Journals with very high impact factors (12 or higher) also cited more contemporary research.

These are observational findings and the authors acknowledge that they assessed only the age and not the relevance of cited studies, and analysed only the first eligible “recent” expression per article. Still, drawing on a large and systematically reviewed sample, they show that “recent” functions as a remarkably flexible rhetorical device in scientific writing. 

They conclude: “This playful analysis suggests that "recent" can mean anything from last season to last century. Readers, reviewers, and editors may want to take "recent" claims with a grain of chronological salt.”