You should reference a Cochrane Library systematic review in a similar way to a journal article. Remember to include the CD number (see example below).
Examples of how to format these in Harvard, APA and Vancouver can be found on the Cite Them Right website. Below is an example of how one looks, in the Harvard style, which the majority of students use:
In-text citation:
Abraha et al. (2017)
Reference list:
Cite Them Right 12th edition style:
Abraha, I. et al. (2017) ‘Simulated presence therapy for dementia’, Cochrane Database of Systematic Reviews, 4, CD011882. Available at: https://doi.org/10.1002/14651858.CD011882.pub2