Q. How can I find duplicates from databases for my PRISMA chart?

Duplicates can be found by using a citation manager, such as Zotero or Mendeley. It is also possible to determine duplicates through a spreadsheet. 

Zotero

1. Create a folder with subfolders for each database
2. Import citations into Database subfolders using either:
   • the Zotero Connector (web plugin)
   • download a .bibtex or .ris file and import into Zotero
3. Include the number of items imported into each subfolder
4. Highlight and drag all the subfolder files into the Parent folder
5. Select Duplicate Items under the My Library menu 
6. Merge any duplicates found
7. Review all the items in the Parent folder to see if there are any remaining duplicates
8. Note number of items in the Parent folder
9. Add the total number of items in the subfolders
10. Subtract the number from the parent folder from the total of the subfolders – this is your number of duplicates.

Mendeley

First you will need to set up a Mendeley account, and download Mendeley Desktop.

1. Create a Parent folder in Mendeley with subfolders for each database
2. Import citations into database subfolders using:
   • the Mendeley web importer 
   • download a .bibtex or .ris file and import into Mendeley 
3. Include the number of items imported into each subfolder
4. Select the Parent folder 
5. Click on Duplicates under the Library menu
6. From here you will see duplicated references grouped into sets. You can delete any unwanted references to resolve a duplicate set.
7. Merge any duplicates
8. Review all the items in the Parent folder to see if there are any remaining duplicates
9. Note number of items in the Parent folder (find the number of items by clicking on one reference, the total number will be displayed at the bottom of the window)
10. Add the total number of items in the subfolders
11. Subtract the number from the Parent folder from the total of the subfolders – this is your number of duplicates.