Systematic Review Guide

Plan Ahead

Decide as a team what tools to use to stay organized. If your team includes people you do not have physical access to, consider using tools that will offer the opportunity to easily collaborate on single documents as opposed to emailing back and forth.

Record Keeping

The goal is to keep records in the most systematic way possible so that all of your work can be reproduced. That means you should keep detailed search strategy, with the date and numbers of results, in addition to saving searches in your personal accounts (like your My NCBI account in PubMed).

Manage your Results

You will need to use bibliographic software that allows you to save large numbers of search results from various databases, remove duplicate results, annotate, and cite the papers. Unity Health Toronto has a site licence to EndNote. Other teams have used such tools as Mendeley or Papers. We no longer recommend Reference Manager or RefWorks.  

Study Selection

Study selection is based on the inclusion and exclusion criteria set out in your protocol. You need at least two reviewers and a tie-breaker to independently screen the results. Generally, this happens in two stages, with the title and abstract screening first, followed by examining the full-text of articles identified as potentially meeting the inclusion criteria. You need to track the reasons why the studies were or were not included.

An Excel spreadsheet organized by article and sub-organized by preliminary inclusion and exclusion criteria would work for this. You can also use software for this purpose such as RevMan, Covidence, EPPI Reviewer, DistillerSR, or Rayyan. You may need a subscription to this software. For a list of software available visit the Software section of this guide. 

Data Extraction

Once you’ve identified the included studies, you will extract the study data for your analysis. Key items for data extraction based on your PICO will be identified in advance and your data extraction tools should be piloted before starting. Note that some of the systematic review software listed on this guide will allow you to create customized data extraction forms. 

Here is an example of a data extraction form by the Cochrane Collaboration for intervention reviews.

Flow Diagram

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.Here is a template of the PRISMA flow diagram.