NOTE: 'It is essential for the search to be as exhaustive as possible to include all potentially relevant articles. Therefore, it is typical that the results of the search include a margin of error and risk-aversion; thus, the initial set of articles to screen could be large and potentially seem overwhelming. However, including a large set of articles at the outset allows the research team greater latitude to be the human filter, adding precision to the inclusion or exclusion of relevant studies. It is better to err on the side of not having the database filter with too much exactitude, to give the team greater control over whether to include or exclude a study.'
Source: Brackett A, Batten J. Ensuring the rigor in systematic reviews: Part 4, screening the results. Heart & Lung. 2021;50(2):182-4. https://doi.org/10.1016/j.hrtlng.2020.11.002
This is a useful paper to read for additional information on the screening process.

Using a reference management tool is a good idea.

See:

• blog on removing duplicates from an EndNote library
• The Information Specialists at the University of Leeds have a useful module on Endnote for reviews.
• Follow this earlier simpler guide from Bramer. A modified more advance version is: Bramer WM, Giustini D, de Jonge GB, Holland L, Bekhuis T. De-duplication of database search results for systematic reviews in EndNote. Journal of the Medical Library Association: JMLA. 2016 Jul;104(3):240.
• The University of South Australia Library has useful information on using EndNote.  Note if you use Covidence for screening you do not need to deduplicate.
• Managing results using EndNote - MD Anderson Center at the University of Texas - click the Tracking results tab. Includes useful instructions on preparing EndNote for finding duplicates.
• Watch the 2 Clarivate webinairs on tips for using EndNote as part of the systematic review process.
• Peters MDJ. Managing and coding references for systematic reviews and scoping reviews in EndNote. Med Ref Serv Q. 2017;36(1):19-31.

Compare reference management tools.