Annual MEDLINE®/PubMed® Year-End Processing (YEP): Impact on Searching During Fall 2008

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Indexed Citations

On November 19, 2008, NLM® expects to temporarily halt the addition of fully-indexed MEDLINE citations to PubMed. NLM indexing staff will continue to index citations, but these completed records will be held and not added to PubMed until the normal update schedule resumes. Once the end-of-year activities are complete (tentatively targeted for mid-December 2008), the normal MEDLINE/PubMed update schedule will resume, and PubMed will use 2009 vocabulary in the MeSH® translation tables and MeSH database, as well as in the citation data.

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, but they have undergone issue level and subsequent citation level quality control reviews.

Searching

A search limiting terms to fields affected by indexing (e.g., telemedicine [mh]) does not retrieve in process or publisher-supplied records (see Data added to MEDLINE records 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 My NCBI and retrieved through RSS feed stored searches - may not retrieve new records for some weeks. To retrieve new, in process records during this time, you should use searches that do not limit to affected fields (e.g., telemedicine). Note that the search terms are not tagged in this example. By mid-December, the in process citations that are within the scope of MEDLINE and that have been indexed since November 19, 2008 will be replaced as indexed citations with 2009 MeSH terms, Publication Types, etc. Searches, including My NCBI Stored Searches, containing tagged search terms will then retrieve all applicable MEDLINE records.

Corrections on Hold

Also as of November 19, 2008, corrections to completed MEDLINE citations (e.g., to correct an author name misspelling) will not be released to MEDLINE. NLM staff will continue to correct completed citations and these will replace the incorrect citations in MEDLINE when the normal update schedule resumes.

Data (with search tags) added to MEDLINE records during indexing:

EC/RN Number [rn] Grant Number [gr] Some grant numbers are added during indexing, but the majority are present while the citation is "in process." MeSH Terms [mh] Includes age groups; Humans/Animals; Male/Female MeSH Major Topic [majr] Publication Type [pt] Many publication types are present on in process records but some are added or revised during indexing. Subheadings [sh] Subset [sb] Citation status values change from "In Process" to "MEDLINE" once MeSH indexing has been completed Substance Name [nm] English [la] is not on this list. Limiting to English language will retrieve in process records.

Other Resources

MeSH

• MeSH Homepage
• New Descriptors, Changed Descriptors, Deleted Descriptors, etc.
• Download Files
• MeSH Browser