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How to Search the Literature (Advanced)

This guide offers an eight step approach from identifying your topic to managing your search strategy and results

Construct a Search Strategy

Searching by subject headings and keywords for each identified search concept is the key to an effective search strategy in a database. 

Question: In patients with lateral elbow pain (P), is surgery (I) effective in improving pain and function (O)?

Patient / Population / or Problem (P) Intervention (I) Comparison / Control Intervention (C) Outcome (O)
Concept A Concept B Concept C Concept D

Lateral elbow 

Tennis elbow

Lateral epicondylitis




Surgical procedures, operative



N / A Improving pain and function

Combining Search Concepts and Search Terms

Boolean Operators are used to combine and define the relationships between your search concepts and terms within each, and among search concepts. Common Boolean Operators include OR, AND, NOT:

  • The OR operator broadens your search results by retrieving records that contain either or both of your search terms

    • e.g. Tennis elbow OR Lateral elbow​

    • Usually, you combine each of the termwithin a concept with the Boolean OR operator
  • The AND operator narrows the search results by retrieving records that contain both of your search terms.

    • E.g. Tennis elbow AND surgery

    • Usually, you combine different concepts with the AND operator
  • The NOT operator narrows the search results by eliminating a specific search term.

    • E.g. Surgery NOT Physical Therapy

    • Use the NOT Operator with caution. It can eliminate relevant results that happen to mention the term you are "notting" out

Using our example above, we can now construct our search strategy using Boolean Operators:

(remember, you should scan the search results for the outcome(s) rather than including these terms as a search concept)