Finding Types of Research

What is a Randomized Controlled Trial?

"A clinical trial in which the subjects are randomly distributed into groups which are either subjected to the experimental procedure (as use of a drug) or which serve as controls —called also randomized clinical trial" (Merriam-Webster, 2016).

Find Randomized Controlled Trials

As with all other studies, one strategy to finding randomized controlled trials is to add the study type to your search string. See example below:

antihypertensives AND "blood pressure" AND "randomized controlled trial"

In addition, there are a few other things you can do while searching individual databases as shown below.

CINAHL and Medline: Publication Type Filter

Randomized Controlled Trial

CINAHL and Medline are databases that allow you to limit your search results to randomized controlled trials only.

To find randomized controlled trials in CINAHL or Medline, follow the steps below:

  1. Enter the database you want to search through the links above. You will be taken directly to the advanced search page. Enter your keyword (s) into the search boxes. 
  2. Scroll down to the Limit Your Results section. This is where you can add filters to your search to tell the database that you only want articles that fit specific criteria. 
  3. Select Randomized Controlled Trial from the Publication Type scroll menu.

PubMed: Randomized Control Trial Filter

To find randomized controlled trials in PubMed, follow the steps below:

  1. Enter the database through the link above.
  2. Search your topic by entering your keywords into the search box and hitting search. 
  3. Select Randomized Controlled Trial from the Article Type section to the left-hand side of the page.

Note! With any of these searches, you will need to limit to full text to get articles immediately available to you.

Example of Randomized Controlled Trial


Merriam Webster. (2016). Randomized controlled trial. In Merriam-Webster (Ed.), Merriam Webster's Medical Dictionary. Merriam-Webster.