How recent is recent? Retrospective analysis of suspiciously timeless citations

Area of Science:

• Bibliometrics
• Scientific publishing
• Biomedical research

Background:

• The term "recent" is frequently used in biomedical articles to imply timeliness of cited evidence.
• However, the actual age of studies described as "recent" is often not reflective of current data.

Purpose of the Study:

• To quantify the time lag between biomedical articles and the studies they describe as "recent."
• To analyze variations in this time lag across different medical specialties and citation expressions.

Main Methods:

• Retrospective analysis of 1000 English-language biomedical articles.
• Structured PubMed search using 20 predefined "recent" expressions linked to citations.
• Calculation of the time lag in years between citing articles and referenced "recent" studies.

Main Results:

• The citation lag for "recent" studies ranged from 0 to 37 years, with a mean of 5.53 years and a median of 4 years.
• 17.7% of references described as "recent" were at least 10 years old.
• Citation lag varied by specialty (e.g., shorter in critical care, longer in nephrology) and expression used (e.g., "recent publication" vs. "recent study").
• High-impact journals and more recent publications showed shorter citation lags.

Conclusions:

• The term "recent" in biomedical literature is applied with considerable flexibility, often encompassing studies decades old.
• Readers and reviewers should critically assess claims of timeliness, as "recent" can be a misleading descriptor.
• Understanding citation lag is crucial for accurately interpreting the currency of evidence in scientific publications.