May 26, 2022

Database Statistics: MEDLINE Milestones (More than 20 Million Citations)

From the NLM:

When all citations now labeled as MEDLINE, including all those created from the OLDMEDLINE project (pre-1966 that have now had all their old keywords mapped to current MeSH) are counted, then MEDLINE achieved 20 million citations on October 16, 2012. This PubMed search shows the running count for MEDLINE which is currently over 22 million citations:

medline [sb]

When excluding the OLDMEDLINE-derived subset, MEDLINE from 1966 forward reached 20 million citations on December 17, 2014. This PubMed search shows the running count for MEDLINE minus the OLDMEDLINE subset:

medline [sb] NOT jsubsetom [sb]

About Gary Price

Gary Price ( is a librarian, writer, consultant, and frequent conference speaker based in the Washington D.C. metro area. Before launching INFOdocket, Price and Shirl Kennedy were the founders and senior editors at ResourceShelf and DocuTicker for 10 years. From 2006-2009 he was Director of Online Information Services at, and is currently a contributing editor at Search Engine Land.