Authors are encouraged to demonstrate how their research informs the existing knowledge base by undertaking a structured background literature review.
Where including a literature search is appropriate the Methods section[s] should include:
All information sources used in identifying studies with the name of the database, the platform or provider used (e.g., OVID, PubMed, Dialog), the date of coverage and the date last searched
Any supplementary sources such as checking reference lists, searching trial registries, any contact with study authors to identify additional studies and Internet searches
Search dates for a literature review, particularly an evidence synthesis project where the results are derived from that literature, must be no more than 12 months old upon first submission of the report to the Editorial Office. However, where a literature review is just one component of a larger study, such as when it forms the basis for subsequent elements of the project, it should be as up to date as necessary for that project.