Systematic Reviews

Role of the librarian in this stage

A librarian can advise you on study selection for your systematic review, including: 

  • How to use Covidence to screen citations and manage the screening process
  • How to apply your review inclusion and exclusion criteria to the screening process

Contact HSL About Your Review

Email us

Ready to start a systematic review? HSL Librarians can help!

Fill out the Systematic Review Request Form and the best-suited librarian will get back to you promptly. Our systematic review service is only available to faculty, staff, students, and others who are affiliated with UNC Chapel Hill.

Helpful Tip - Preliminary Testing and Screening

One of the most important aspects of screening citations is to make sure the team adequately understands how to properly apply the inclusion and exclusion criteria to the citations being screened. It can be especially helpful for screeners to undertake preliminary/test screening on a subset of articles to ensure agreement. Test screening can be performed in Covidence or Excel. While adding this step may add some time initially, it will most likely expedite both screening phases after as screeners will be more comfortable applying the inclusion and exclusion criteria properly and most likely result in less error or conflicts.

Screening Results with Covidence

How does screening work in Covidence?

Once you have completed literature searching and compiled all citations, it is time to screen the results. The purpose of screening is to eliminate studies that do not meet your inclusion criteria. Two independent reviewers should screen all studies, starting with a title and abstract screening, followed by a full-text screening. A third reviewer should resolve any conflicts.

During the title/abstract screening, for each reference, each reviewer should read the title and abstract and make a decision:

  • No: This article does not meet inclusion criteria and should not be included in the systematic review.
  • Maybe: There is not enough information in the title/abstract to make a decision (move to full-text screening stage).
  • Yes: This article appears to meet inclusion criteria and should move to the full-text screening stage.

During the full-text screening, for each reference, read the full-text and make a decision:

  • Include: This article meets inclusion criteria and should be included in the systematic review.
  • Exclude: This article does not meet inclusion criteria and should not be included in the systematic review.

Remember, all voting should be blinded, meaning team members should be unable to see how others cast their votes.

Reporting Standards for Systematic Reviews (PRISMA)

"PRISMA stands for Preferred Reporting Items for Systematic Reviews and Meta-Analyses. It is an evidence-based minimum set of items for reporting in systematic reviews and meta-analyses. The aim of the PRISMA Statement is to help authors improve the reporting of systematic reviews and meta-analyses. The PRISMA Statement consists of a 27-item checklist and a four-phase flow diagram." (From prisma-statement.org )

In your review, you will need to track the number of results from each database you search, the number of duplicates you remove, the decisions you make on each article, and in the full text level, the reasons why you exclude articles. More information and a step-by-step guide can be found on the Using PRISMA for Reporting page on this guide.


PRISMA and Covidence:

Covidence will track numbers of citations screened at each stage and how many are ultimately included in the review. These numbers can be copy and pasted into a PRISMA diagram template. You will still need to record the number of results from each databases search and the number of duplicates removed from your set of articles.