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Systematic Reviews

Steps to Develop a Search Strategy for Your Systematic Review

Creating a search strategy can feel overwhelming—but with a clear plan and structured steps, the process becomes much more manageable.

🔍 Step 1: Gather Background Information

  • Start by identifying 3–10 target articles. Your target articles should fit your topic.
  • Use these to:
    • Discover potential search terms.
    • Validate your search strategy (make sure these articles appear in your results).
  • If they don’t appear:
    • Check if they meet your inclusion/exclusion criteria.
    • Adjust your strategy to ensure it's comprehensive.

❓ Step 2: Formulate Your Research Question

  • Some inclusion/exclusion criteria can be built into your search.
  • Others are better applied during screening.
  • Choose criteria for inclusion/exclusion (e.g., date, language) carefully and document your rationale.

📌 Don't forget to:

  • Select appropriate databases.
  • Search for grey literature.
  • Include hand searching.

🧠 Step 3: Identify Key Concepts

Start with one familiar database and:

  • Brainstorm keywords.
  • Check for controlled vocabulary (e.g., MeSH in PubMed, CINAHL Headings).
  • Use:
    • Phrases: "pediatric migraine"
    • Wildcards: wom#n → woman or women
    • Truncation: child* → child, children, childhood

💡 Pro Tip: Use the Yale MeSH Analyzer to extract and compare terms from up to 20 PubMed articles.

🎯 Step 4: Choose Search Fields

  • In PubMed, target:
    • [Title/Abstract]
    • [Text Word] (includes author-assigned keywords)

🔗 Step 5: Combine Terms with Boolean Operators

  • AND: Both terms must appear
  • OR: Either term can appear
  • NOT: Exclude specific terms (e.g., common cold NOT cold temperature)

💡 Pro Tip:
Run one concept at a time:

  1. Combine all terms for Concept 1 with OR
  2. Combine all terms for Concept 2 with OR
  3. Then combine both concepts with AND

🧪 Step 6: Run and Refine Your Search

  • Run your search multiple times.
  • Tweak terms as needed.
  • Apply limits (e.g., language, date) only after finalizing your strategy.
  • Avoid using filters like "age group" or "human"—search these as concepts instead.

🗂️ Step 7: Document Everything

Keep a record of:

  • All search terms used
  • Search strings or exported spreadsheets
  • Filters applied
  • Date of search
  • Number of results

💡 Pro Tip: Use Cochrane’s Search Report Template to document your strategy.

💾 Step 8: Save and Reuse Your Search

  • Create a free account in each database.
  • Save your search and set up alerts for new articles.

🌐 Step 9: Search Other Databases

  • Adapt your strategy for each database.
  • Remember: MeSH terms may not apply outside PubMed.

What is Grey Literature?
Cochrane Handbook defines Grey Literature as "...literature not formally published in books or journals. This can include theses or dissertations, conference proceedings, clinical trials registries, white papers, government reports, and more."

Where can I find Grey Literature?

  • clinicaltrials.gov
  • Google Scholar
  • Scopus

What is Hand Searching?
Handsearching is the task of searching through medical journals, conference abstracts, references lists, and/or books for reports of controlled trials which are not indexed in the major electronic databases like MEDLINE and Embase. For complete identification of reports of trials, electronic searching may need to be supplemented by conducting page by page searches of a variety of sources including journals and supplements, conference proceedings and abstracts, and correspondence.

From https://training.cochrane.org/resource/tsc-induction-mentoring-training-guide/5-handsearching