Skip to main content

Systematic Reviews: A How-To Guide

Overview of systematic review steps and resources to assist researchers conducting reviews

Systematic Searching

Systematic searching requires a set of skills and techniques that you may not have encountered in your previous research. In addition to guiding you to key databases and other sources of information, these pages offers some tips on systematic search methods.

Your Search Process

The search process for your systematic review might look something like this:

Preliminary Searches (non-systematic)

Conducting some preliminary, non-systematic searches on your topic will help you to:

  • help identify key terms and synonyms;
  • find existing systematic reviews on any component of your topic and review search strategies included in methods or appendix; and
  • locate some target, likely to be included, articles through non-systematic searching (using related articles functions, basic searching, etc.).
Overall Final Comprehensive Search Process (systematic)

When you are ready to conduct your systematic search, consider the following process:

  1. Identify terms for each concept
    • Also discuss best sources to search with a librarian (e.g. PubMed, Embase, CINAHL, Cochrane, etc.)
  2. Run search in first database
  3. Translate search to other database(s)
  4. Compile results from all databases and remove duplicates to prepare for screening
  5. As studies to include emerge from the screening process, check the references and whether the included study has been cited (use Scopus, Web of Science, and/or Google Scholar)
  6. Determine relevant grey literature sources and search with modified strategies (includes trial registries, conference proceedings, theses and dissertations, etc.)
  7. Contact experts, including corresponding authors of included studies, to find out about additional or ongoing studies
  8. Hand search additional non-indexed journals or conference proceedings, if appropriate
  9. Update search if significant time elapsed since initial search

Core Databases

In addition to these core health sciences databases, consider searching databases outside of the health sciences that might be relevant to your topic. Consult Dalhousie Libraries' subject guides to learn more about resources for other disciplines:

Searching for Existing Systematic Reviews

The ideal first step in the systematic review process is to see if other reviews have been published on your topic, or if relevant research is in the process of being completed. Existing systematic reviews and protocols can be found in the following places:

You can also use search filters to locate systematic reviews in other databases.

Translating Searches

Not all databases use the same syntax. When translating a search strategy from one database to another, you will have to make some changes to get comparable results. This video demonstrates how to translate a search strategy from PubMed to CINAHL and Embase.

Video opens in a new tab.

Search Translation Resources

The video below shows the process of translating a final search from MEDLINE Ovid to the Cochrane Library, including changes to search syntax. This video was created by librarians at the Gerstein Science Information Centre at the University of Toronto. There have been some changes in the layout of the Cochrane Library since this video was made, but the search functions are the same.

Search Tutorials - Dalhousie Libraries

Search tools and visualization