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Systematic Review

This guide aims to provide tools and resources that can be used for conducting a systematic review in medical and health sciences.

Two Stages of Screening

Take note on the following points before screening search results:

  • Duplicate records of your search results should be removed before starting the screening process.
  • At least two team members should work independently on screening the papers to reduce the risk of missing papers or bias in the selection process.
  • Papers must be selected based on the research question and eligibility inclusion & exclusion criteria defined in the Planning process.

There are two stages of screening of papers:

 Title and abstract screening: 

Each reviewer will need to read titles and abstracts of the papers to see if they match the inclusion & exclusion criteria. This is done separately by each reviewer. After both reviewers have evaluated the studies, votes are compared.

 Full-text screening:

In the second round of screening, members evaluate the remaining studies by reading the full-text articles. Members must record the reasons for excluding studies based on the pre-determined inclusion & exclusion criteria.

Ideally, study selection is completed by two independent reviewers with a third person available for resolving conflicts. Alternatively, disagreement of study selection may be resolved by discussion between the reviewers. 

Tools can help with the Screening Process

Covidence (fee based, CUHK library subscribed) is a web-based software platform that streamlines the production of systematic reviews and other research reviews. It makes it easy to screen references (both title/abstract and full-text), create data extraction forms, and complete the risk of bias tables. You can also divide up the work among your team of reviewers and track the progress of the project.

With Covidence you can easily combine and import papers from multiple databases in the search process. Duplicated papers are automatically removed once they are imported to the platform. Reviewers can then work independently on the screening process.

Other SR tools which supports the screening process are:

  • Abstrackr (free tool) - allows you and your team to screen, organize, and manipulate all of your abstracts in one place.
  • DistillerSR (fee based)
  • Rayyan (free tool) - can be used for finding and removing duplicates, screening, and selecting studies for reviews.

Reporting Your Search: PRISMA Statement

PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) is an evidence-based minimum set of items for reporting in systematic reviews and meta-analyses. 

  • PRISMA 2020 flow diagram is used for further documentation of the number of records identified from database, registers and through other sources. The flow diagram depicts the flow of information through the different phases of a systematic review. It maps out the number of records identified, included and excluded, and the reasons for exclusions.

  • PRISMA Checklist contains 27 items addressing the introduction, methods, results and discussion sections of a systematic review report.
  • PRISMA for Searching (PRISMA-S) is a 16-item checklist that covers multiple aspects of the search process for systematic reviews. It is intended to guide reporting, not conduct, of the search.

Click Searching: Recording & Reporting for more resources on reporting your searches in Cochrane systematic reviews.