Whatever type of review you are working on, you will need to provide some information on the following:

• Total number of references/studies imported

• Number of duplicates removed

• Number of references screened

• Number of full-text references assessed for eligibility

• Number of studies excluded (with reasons)

• Number of references/studies included in the review

This information should ideally be accompanied with a flow diagram. The flow diagram can be exported directly from Covidence and edited if required. 

An example of how to include this information in your results section is provided below. 

Example of item 16a of PRISMA 2020 checklist

“We found 1,333 records in databases searching. After duplicates removal, we screened 1,092 records, from which we reviewed 34 full-text documents, and finally included six papers [each cited]. Later, we searched documents that cited any of the initially included studies as well as the references of the initially included studies. However, no extra articles that fulfilled inclusion criteria were found in these searches (a flow diagram is available at https://doi.org/10.1371/journal.pone.0233220).”

Source of example: Page M J, Moher D, Bossuyt P M, Boutron I, Hoffmann T C, Mulrow C D et al. PRISMA 2020 explanation and elaboration: updated guidance and exemplars for reporting systematic reviews BMJ 2021; 372 :n160 doi:10.1136/bmj.n160