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Evidence-Based Clinical Practice

A guide to EBCP and resources.

Practice Using PICO

Background vs. Foreground Question

Background questions typically begin with what, when, why, where and how.  In clinical medicine, they relate to information that will help you form a more focused, foreground question in the future.  These types of questions are often answered by general medicine textbooks, such as Harrison's Principles of Internal Medicine, articles found in UpToDate, or general review articles.   These types of questions are usually to general for a traditional literature search.  

Foreground questions are asked in very specific ways; in the case of Evidence Based Clinical Practice, using the PICO format.  These questions discover information about specific types of medicine, namely diagnosis, prognosis, treatment, or etiology.  Foreground questions can be answered with medical literature, specifically using the MEDLINE database.  As clinicians become more established they tend to ask more foreground and fewer background questions, having already acquired much of the background knowledge in their fields.  

Framing a Foreground Question

Whether you are starting a research project or answering a clinical question, having a well-formed question defined by the Ask step is key.

PICO is a useful mnemonic used to describe the four elements of a good clinical question:

P = Population - How would I describe the problem or a group of patients similar to mine?

I = Intervention - What main intervention, prognostic factor or exposure am I considering?

C = Comparison - Is there an alternative to compare with the intervention? The alternative can also be placebo or no treatment.  

O = Outcome - What do I hope to accomplish, measure, improve or affect?

There are also versions of PICO with time and type of study included as a part of the question.  Those can be abbreviated as PICOT or PICOT(T).

PICO Examples


Population (Patient/Problem)

Intervention Comparison Outcome
Description Describe as accurately as possible the patient or group of patients of interest. What is the main intervention or therapy you wish to consider?
Including an exposure to disease, a diagnostic test, a prognostic factor, a treatment, a patient perception, a risk factor, etc.
Is there an alternative treatment to compare?
Including no disease, placebo, a different prognostic factor, absence of risk factor, etc.
What is the clinical outcome, including a time horizon if relevant?
Example In patients on oral antibiotics do probiotics none prevent diarrhea?
Example In children with cancer what are the current treatments none in the management of fever and infection?
Example Among family members of patients undergoing diagnostic procedures does standard care, listening to tranquil music or audio taped comedy routines make a difference in the reduction of reported anxiety?


Using PICO to Acquire Evidence

Once you have a clear clinical question, you can acquire the necessary evidence to answer it. See the "Step 2: Acquire" page of this guide to learn how to translate PICO into a search strategy.