Systematic Reviews

This step is conducted primarily by the librarian or information specialist on the team, following the protocol developed in step 3.  Content experts can help by providing exemplar articles of either recent studies that would be included, or previous systematic reviews.

Working from the protocol developed by the team, the librarian or information specialist will

• Construct exhaustive search filters to capture each concept of the PICO question
• Apply Boolean logic to create a meaningful search query
• Launch an initial search in PubMed or Embase
• Send investigator the search strategy, any field notes with highlighted observations, and initial results

After search results have been received, the lead investigator will review results and provide feedback by…

• Reviewing search query for missing words and/or any words that do not belong
• Spot check search results for things like…
  • appropriateness to your research question
  • a concept that keeps coming up that is different from your research question
  • key concepts in your research question that are consistently missing from the search results

Constructing search strategies is complex and time consuming. The librarian cannot move forward without feedback from the investigator.  The search developed at this stage will be the basis for all of the database searches in the next step.

The PRESS: Peer Review of Electronic Search Strategies process was developed and most recently updated in 2015 as a guideline for assessing a search strategy developed by another.  The guidance focuses on evaluating:

• Translation of Search Question
• Boolean and proximity operators
• Subject headings
• Text word searching
• Spelling, syntax, and line numbers
• Limits and filters

A PRISMA extension for searching was published in 2021, and provides more detailed guidance in how to report a search in your manuscript in a 16-point checklist, which examples and explanations.

Search hedges are pre-defined search strategies for searching common topics, often publication types or study designs.  These are combined with a general topic search to refine your results.  Often there is a trade off between sensitivity or recall (not missing anything) and precision (not getting irrelevant results), so multiple strategies may be presented.

This blog features comprehensive PubMed searches combining keywords and MeSH terms. Visit the blog to browse or search for a pre-formulated search on your topic. You can then copy and paste the search into PubMed@UToledo and use the Advanced Search link at the top to combine the results into your own search strategy. Remember, the Mulford Reference Librarians can help you formulate a comprehensive search strategy as well!

A few recent search strategies featured on the blog include: