Using the entry date field tag (EM), you can retrieve citations added to the CINAHL or MEDLINE databases at a specific time. To search the most current articles of the database, the entry date field code is essential. Date format can be YYYYMM or YYYYMMDD. For example:
- Type: critical care and EM 200012
In the example above, the entry month field will produce only results concerning critical care entered into the database in December 2000. Note: you can use a hyphen to indicate an open-ended date range. Entering a hyphen either before or after an entry month will find results "on or before" or "on or after" the date entered.
Example: type nursing home and EM 200012- (to retrieve articles about nursing homes entered from December 2000 to the present).
Example: type twins and EM -200012 (to retrieve articles about twins entered previous to and including December 2000).
Why does my MEDLINE search limited by "Entry Date" have more results than it did before?
The entry date field represents the date (CCYYMMDD) that the National Library of Medicine (NLM) first created the citation. This is the "Date Created," or "Entry Date," that is represented by the field code EM in the MEDLINE databases.
After the NLM has created the citation, the data is sent to EBSCO and uploaded to the MEDLINE databases. The date that it is uploaded to EBSCOhost is considered the "Date Completed" and will have the Entry Date posted as well.
It is possible to receive higher results for a search limited by a fixed range of entry dates if citations with an Entry Date within the range searched have been added since the user's previous search.