Skip to Main Content
Circulation Desk
Email a Librarian

PICO Research Questions: PICO in the Databases

This guide provides tips for creating PICO research questions and searching the databases.

Searching Using PICO Questions

These health and nursing databases are popular in searching for evidence-based articles from your PICO question:

Searching the Databases

Now that you have broken down your PICO question, it is time to search the databases.

Boolean Logic

  • Most databases and search engines understand at least three of the main logic operators: AND, OR, NOT
    • An operator is a word that is read as something the engine DOES, not as a word to search
    • Operators allow you to combine keywords in different ways
  • AND
    • Tells the database to find articles with both of the terms.
    • This narrows your results.
  • OR
    • Tells the database to find articles with either, both, or any combination of the terms.
    • This expands your results.


  • NOT
    • Tells the database to not show you ANY articles that used the term(s) indicated after NOT.
    • This narrows your results.

Database Filters

The results pages on these databases usually have a menu on the left-hand side of the screen. The menu has a set of filters that can help you narrow down your results. These include age, sex, location, and more. Only use these once you have looked at the original results...they severely narrow down your results! 

Cochrane Library's PICO Search Beta is new to their services. You can use your PICO elements to search for Cochrane Reviews related to your PICO question.

You can also find PICO terms used in the Cochrane Library by searching your topic in the Advanced Search on Cochrane.

  • Click on the Cochrane Reviews tab on the results page. 
  • Show PICOs Beta link can be found under the title of the article. When you click on this, you can see the PICO terms used to describe the articles.

To learn more about getting started with PICO Search Beta, look at these two tutorials.

Once you have entered your search terms into the database, narrow down your search by limiting to date range and to “Evidence-based Practice.” You may also narrow your search down to document types such as:

  • Case Studies
  • Clinical Trials
  • Meta-analyses
  • Randomized Control Trials
  • Research
  • Systematic Reviews

Select articles with the highest level of evidence (meta-analyses and systematic reviews). These will yield the best available evidence to support your clinical decisions and explore alternative interventions or treatments to health-related problems in the field.

More information on the types of documents and where they can be used can be found in the Levels of Evidence tab in this research guide.