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Physician Assistant: A Research Guide


PICO is a method of developing a research question for the health sciences. Following this method ensures that specific elements appear in the question. Due to the consistent structure of these questions, there is a matching search method. In a PICO question and search, there are four factors used:


P Population Patient / Group / Health concern
I Intervention Action / Treatment under study
C Comparison Comparative action / Placebo / Standard of care
O Outcome Anticipated outcome


A PICO question might look like:

In population, what are the effects of intervention versus comparison on outcome?

In population, what is the relationship between intervention and outcome?


Sometimes, a T will also be included, forming a PICOT question. The T might have two different meanings:

T Time Time Frame
T Type Type of Study/Question


PICO Keywords

The PICO question is only the start of the search. Before you begin searching, brainstorm keywords for each term. Here is an example:


Question: Does coloring help college students destress?

  Question Words Keywords
P college students "college student", "university student"
I coloring color, coloring, colour, colouring
C (not coloring)  
O destress destress, stress, calm, anxiety

Note the quotation marks around "college student" and "university student." They tell the database that these are phrases and the words should be searched together. 

Search Strategy

There are two typical structures for a PICO Search

P and I and O

P and (I or C) and O


Including keywords the search will look more like this:

(P or P or P) and (I or I or I) and (O or O or O)

(P or P or P) and ((I or I) or (C or C)) and (O or O or O)


In a database with multiple search boxes, you can put all of your P keywords together in one box, separated by OR. Then, put all of the I keywords in the next box, etc. Connect the boxes with AND.

For the nested search in the second structure, you can use EBSCO's search history tools to search each section of PICO separately and then connect them with AND/OR as appropriate. However, it is likely easier to search PIO and PCO separately.


From the above example, for the question, "Does coloring help college students destress?" our search will look like:

("college student" OR "university student")

AND (color OR colour OR coloring OR colouring)

AND (destress OR stress OR calm OR anxiety)