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Systematic searching: 10. Updating a search

Updating a search


Sometimes you may need to update database searches. This may be because:

  • you continue working on a review and previous searches have already been outdated. The Cochrane Handbook states that "The search must be rerun close to publication, if the initial search date is more than 12 months (preferably six months) from the intended publication date, and the results screened for potentially eligible studies".
  • your manuscript has been under review process for several months. Journals may request that searches be re-run prior to publication, if months have passed since submission
  • you are updating a previously published review

This page will show you a few methods of updating a search in different databases. This will speed up your screening process because you don't have to screen all your records again.

In updating the search, you will be trying to find:

  • new material that has been published prior your last searches. These can be found using publication date limiters.
  • records for older material that have recently been added to the databases. These can be found using entry date, create date) limiters. These will include both new and recently added references.


  • Not all databases allow you to search by "create date" or "entry date". Hereby publication date must sometimes be used.
  • If you haven't undertaken screening yet, you can simply re-run your searches in your chosen databases.
  •  In Covidence, you can simply import all the records generated by the new/updated searches, and Covidence will remove records that have already been uploaded.
  • The longer the time that searches have been run, the more important it is to check if there has been any changes in databases' search functions. These changes may include changes in field codes, database sources and indexing. MeSH is updated annually. New terms are added and some terms are changed. Information specialist can help you with the database check ups.



University of Southern Australia Library. 2023. Updating a search. In guide: Systematic reviews. 

McGill Library. 2023.  Updating the database searches. In guide: Systematic Reviews, Scoping Reviews, and other Knowledge Syntheses.


Database Search command Example 




EM (Entry Date) can be used with a hyphen ('on or after' the date) or range.


Use AND to join this line to the last line of your search.

EM 20211115-20231009

Searches references added between 15.11.2021-9.10.2023



Searches references added since 1st Jan 2021. 



CRDT: Creation date 

EDAT: Entrez date 

Date format is YYYY/MM/DD

Use AND to join this line to the last line of your search.

More information on PubMed field codes

#x AND ("2019/07/01"[CRDT] : "3000"[CRDT] OR "2019/07/01"[EDAT] : "3000"[EDAT] 


Limits to references that have been added after 1st July 2019.




Ovid Medline


Date format is YYYYMMDD

x is the number of the final row of your search.

Create date (.dt.) in Ovid MEDLINE is the date when the record was created.

limit 10 to dt=20191115-20221009

Limits line 10 to between 15th Nov. 2019-9th Oct. 2022.



Use AND to join this line to the last line of your search.


Searches references that have been loaded since  14.11.2017.

Web of Science

Index date (LD) can be added in two different ways:

1. (Advanced search) -> Add rate range -> Custom. 

Date format YYYY-MM-DD.

2. Enter the field code directly in the Query Preview box: 


Index Date: 2017-11-15 to 2023-10-09

Searches references added between 15.11.2017-9.10.2023


Searches references added between 15.11.2017-9.10.2023


Only publication date limiter is available: Limits -> Cochrane Library Publication date. 

In Central only publication year limiter is available. Limits-> original publication year.