In Turn Your Questions Into Search Terms, we came up with a list of medical terms we can use in databases. Now, think about the relationship between those terms.
Some terms are synonyms of each other. Because they mean the same thing, we only need one of them to appear in an article. For our football example, we want articles to show up if they use the term "teenager" OR "adolescent," but they do not need to contain both.
For other terms, we only want to see articles if both terms appear. In our football example, we're asking how helmets impact head injuries, so we need articles to contain both "head trauma" AND "head protection".
The terms "AND" and "OR", also called "boolean operators," work in almost every database and let you describe the relationship between terms.
Use OR between terms when the terms are interchangable, and you want to view articles that include either or both.
Use AND between terms when you only want to see results that include both terms.
Imagine you're using a PICO search to compare injury risk with early versus delayed ACL surgery for adolescents. Start by identifying your initial key terms:
Population: adolescents
intervention: delayed ACL reconstruction
Comparison/Control: ACL reconstruction
Outcome: risk
Now, let's think of some other words we can use to cover more area, and add them to the terms using OR:
Population: adolescents OR teenagers OR teen OR youth
intervention: nonoperative OR delay OR delayed OR rehabilitation alone
Comparison/Control: acrl OR acl reconstruction OR anterior cruciate ligament reconstruction
Outcome: risk
Finally, we'll connect these terms using AND. Notice the use of parenthesis to group terms. Parenthesis work the same way they do when performing a math equation, helping to group words/phrases together in the order of operation:
(adolescents OR teenagers OR teen OR youth)
AND
(nonoperative OR delay OR delayed OR rehabilitation alone)
AND
(acrl OR acl reconstruction OR anterior cruciate ligament reconstruction)
AND
risk
Ta-da! This is a complete search query. When a query looks like this, you can copy and paste it into most databases, and it will read the AND, OR, and parenthesis exactly the way we intend. You can also utilize the "Advanced Search" feature in most databases and split each term into a new box. In this case, you can omit AND, since the database will automatically assume an AND relationship between boxes. Here's how the Advanced Search would look in the database CINAHL:
Go to CINAHL and try it out! Try experimenting with different terms, or with adding and removing terms, and see how it impacts the results.
