Mendeley would not usually be considered as the best choice of software for a full systematic review. Especially if your review involves downloading a large number of references, or you are planning on publishing your review, we would recommend using EndNote software for your review instead of Mendeley. It is much more transparent about which items are identified as duplicates and has much greater flexibility relating to checking and removing duplicates. This is likely to significantly reduce the risk of accidentally removing items that are not duplicates and is more thorough when working with large sets of references.
Make sure you are aware of the reporting requirements for the methodology of your review and check that Mendeley will be suitable for providing the data required for that before you start using Mendeley for your review.
Below is detailed a step by step process for using Mendeley for your review.
It's recommended to keep backing up your Mendeley desktop library as you add new sets of references by syncing it with the online version of Mendeley.
For each source you search, create a folder in Mendeley where you will add these references to your library.
Export the references from each source in turn to the appropriate folder in your Mendeley library.
Make sure you record the number of references exported from each database before you import the references into Mendeley, as when you add references to your library it will start removing references it recognises as duplicate references. In practice this means while you might export 50 references from a database, there may only be 45 appearing in the folder if some are duplicates.
It can also be useful to tag all references in the folders with the name of the database or other source so you can tell which database the reference was originally downloaded from. To do this, highlight all items in the folder and edit the reference that is open in the right hand pane by adding the name of the database or other source to the tag field, e.g. Medline. This will update all of the tag fields in references in that folder.
Once you've added your references to your Mendeley library from all your sources, drag all the records from each of the individual folders into another new folder, from which you will remove duplicates. Mendeley may recognise and remove additional duplicates at this stage, so you may find the number of records in this folder does not total the number in your individual folders.
Now use Mendeley's duplicate checking tool to find the remaining possible duplicates. Click on the folder that includes all your references for your review to do this.
Make sure that you check the duplicates thoroughly by clicking to expand the reference sets before merging them. After you have merged all the duplicates, it is recommended to do a final manual check for duplicates on the folder containing all your references, by clicking on the title column of the central pane to order them alphabetically.
If you're working with multiple reviewers to screen your references and want to use a reference management software to do so, we recommended using EndNote, following the methodology linked on our EndNote guide.
If you are planning to use reference screening software such as Rayaan or Covidence, however, it is possible to export your references from Mendeley as a RIS file, though please note this will export all references in your Mendeley library. The same methodology can be followed as for the instructions on our EndNote guide. It is also recommended to deduplicate references in Mendeley before transferring them to a screening software.