he National Library of Medicine (NLM) is now involved in MEDLINE year-end processing activities. These include changing the Medical Subject Headings (MeSH^®) on existing MEDLINE citations to agree with the 2002 version of MeSH, and other global changes such as changes to journal title abbreviations or Supplementary Concept Substance Names. For details about 2002 MeSH changes, see the article, What's New for 2002 MeSH in this issue [updated].

During end-of-year activities, NLM's schedule for adding indexed citations to MEDLINE and PubMed is temporarily interrupted. Once the end-of-year activities are complete (tentatively targeted for January 2002 [corrected]), the normal MEDLINE/PubMed update schedule will resume, and PubMed will use 2002 MeSH in its translation tables and MeSH Browser as well as in the citation data.

Indexed Citations
As of November 2, 2001, NLM will temporarily halt the addition of new, fully-indexed MEDLINE citations to PubMed. NLM indexing staff will continue to index citations and PubMed will be updated to reflect the full-indexing when the normal update schedule resumes.

In-Process Citations
During end-of-year activities, "in-process" citations will continue to be added to PubMed. As a result, the number of PubMed records labeled [PubMed - in process] will temporarily increase. These citations do not have MeSH terms, and the bibliographic citation data (e.g., pagination values) have not been checked for accuracy.

Searching
A search limiting terms to fields affected by indexing, e.g., robotics [mh] AND review [pt], will not retrieve in-process or publisher-supplied records. (See a list of fields added or supplemented during indexing).

Therefore, during end-of-year activities when we are not adding completed, indexed citations to MEDLINE/PubMed, such searches, including those stored in the Cubby, may not retrieve new records for some weeks. To retrieve new, in-process records during this time, consider not limiting searches to affected fields, e.g., robotics review. (Note that the search terms are not tagged in this example.)

By January, the in-process citations that are within the scope of MEDLINE will be replaced by indexed citations with 2002 MeSH terms, Publication Types, etc. Also, the citation bibliographic data will have been checked for accuracy. Searches, including Cubby Stored Searches, containing tagged search terms will then retrieve all applicable MEDLINE records.

Corrections on Hold
Also as of November 2, 2001, corrected citations for MEDLINE journals (e.g., because an author name was misspelled) are not being added to MEDLINE. NLM staff continue to correct citations and these will replace the incorrect citations in MEDLINE when the normal update schedule resumes.

MEDLINE^®/PubMed^® End-of-Year Activities. NLM Tech Bull. 2001 Nov-Dec;(323):e2.