If you use OVID to search Medline, have you noticed it has been stuck on the "December week 4 1999" update for several weeks?
Normally, MEDLINE is updated weekly and runs a couple of weeks ahead of the calendar. What is going on? Every year in January, the National Library of Medicine (NLM) updates its Medical Subject Headings (MeSH) to reflect growth and change in medical language. OVID programs the changes, releases a "global update" at the end of January, then resumes our normal weekly updates in February.
Medical informatics; Online databases
Library and Information Science
Ipri, T. A.
Medline global update due.