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Systematic Reviews

A guide directing researchers on the systematic review process. Layout based on Doing a Systematic Review: A Student's Guide, 2nd Edition, by Angela Boland, M. Gemma Cherry, and Rumona Dickson.

Literature Searching

When searching for relevant literature to your research question, you'll need to determine what terms you're using to search and where to search.


Comprehensive Searching

One of the most important factors in searching is to document a search. Reporting search strategies is required for systematic review authors.

Documentation is also necessary for refining previous searches. Use a Word document (or similar) to keep track of search terms.

When searching, consider:

  • Keywords
  • Synonyms
  • Types of studies
  • Subject Headings (E.g. MeSH (PubMed), CINAHL, and APA Thesaurus to name a few)
  • Spelling variants (i.e. color vs. colour, randomised vs. randomized).

Additional tips:

  • Refer to relevant resources for finding new keywords or search terms
  • Snowball citations - follow cited works in studies yielded by a search to find additional references
  • Include grey literature and nontraditional searches
  • Hand search for articles (see Cochrane for information on hand searching)
  • Review international studies, and note planning strategies relating to translation
  • Search Like a Pro - tips from Covidence
  • Consult a librarian for assistance


Selecting Databases

Knowing where to look for studies is key to a successful review. Below is a link to Duquesne's database list. The databases to search in conducting a systematic review rely heavily on the field a research question is based in.

It's important to revise a search strategy and terms for every database used! Keywords and subject headings in one database may not be the same in another. If you have further questions, feel free to meet with a librarian to discuss where to search.

Translate Your Search Terms with Polyglot

When conducting a literature search, it's important to change search terms based on the classification systems and subject headings within individual databases. For example, CINAHL subject headings may use different terminology when compared to PubMed's MeSH.

Bond University offers Polyglot, a tool for converting search terms from one database into searchable materials for other databases. Part of the University's systematic review accelerator, Polyglot offers search translations for many databases, including CINAHL, PubMed, Embase, APA PsycInfo, Scopus, and more!

Grey Literature

Searching for grey (or gray) literature is necessary for preventing selection bias: that is, searching literature that has not been published. 

Learn more about what grey literature entails and where to search for it on Gumberg's Grey Literature library guide.


More Places to Search

  • Clinical trials

Search National Institute of Health's Clinical Trials registry and York Health Economics Consortium's Finding Clinical Trials

  • Examine reference lists

When relevant studies are found, look at the works cited to find more studies to include in the review. This is called snowballing.

  • Citation searching

Pace University has a great guide to help with citation searching.

  • Perform an Internet search

Using a variety of web browsers, search for a topic. This may lead to individuals or organizations who have done studies pertaining to the research question. Contact these people and organizations to see if they have any unpublished studies to include.