Skip navigation

1.1 Formulate a PICO question

Use the PICO framework to build your question

Before starting a literature search, you must consider what are you looking for and where you might find it.

Many clinical or research questions can be divided into four components, which we call ‘P I C O’.

Try to use all four parts of the question, if possible in your literature search!

P= Population and Problem
I= Intervention
C= Comparator
O= Outcome

Population and Problem
How would you describe a group of patients similar to yours? What are the most important characteristics of the patient? This may include the primary problem, disease, or co-existing conditions. Sometimes the sex, age, or ethnicity of a patient might be relevant to the diagnosis or treatment of a disease.

Intervention
Which main intervention, prognostic factor, indicator, or exposure are you considering? What do you want to do for the patient? Prescribe a drug? Perform a surgery? Order a test? What factor may influence the prognosis of the patient? Age? Co-existing problems? What was the patient exposed to? Asbestos? Cigarette smoke?

Comparator
What is the main alternative to compare with the intervention? Are you trying to decide between two drugs, a drug and no medication or placebo, or two diagnostic tests? Your clinical question may not always have a specific comparison.

Outcome
What can you hope to accomplish, measure, improve or affect? What are you trying to do for the patient? Relieve or eliminate the symptoms? Reduce the number of adverse events? Improve function or test scores?

Example PICO


Should HIV-positive pregnant patients take ART to prevent mother-to-child transmission (PMTCT) of HIV?


P= HIV-positive pregnant woman
I= ART
C= (no treatment)
O= decrease of the risk of mother to child transmission