Graduate College Library Orientation

PICO is an acronym for

• Patient
• Intervention
• Comparison
• Outcome

PICO is used to create a researchable question based on a clinical situation you have encountered.  Based on your PICO question, you will identify keywords and/or subject terms to use in database searches. 

You can use PICO to develop your clinical question.

P - Patient or population/disease: Which population are you studying? (Consider age, gender, ethnicity, group with a certain disorder, etc.)

I - Intervention, prognostic factor, or exposure: What do you want to do for the patient? (Consider therapy, exposure to a disease, risk behavior, prognostic factor, preventative measure, or diagnostic test)

C - Comparison or control: Are you comparing two interventions or variables? (Consider absence of disease, absence of risk factor, or use of placebo)

O - Outcome: What is the expected result or what do you hope to accomplish, improve or affect? (Consider disease incidence, accuracy of a diagnosis, rate of occurrence of adverse outcome, survival or mortality rates)What is the expected result or what do you hope to accomplish, improve or affect? (Consider disease incidence, accuracy of a diagnosis, rate of occurrence of adverse outcome, survival or mortality rates)

Figure from Tree of different types of studies, CEBM, https://www.cebm.net/2014/04/study-designs/

"Spotting the Study Design

The type of study can generally be worked at by looking at three issues (as per the Tree of design in Figure 1):

Q1. What was the aim of the study?

1. To simply describe a population (PO questions)  descriptive
2. To quantify the relationship between factors (PICO questions)  analytic.

Q2. If analytic, was the intervention randomly allocated?

1. Yes? RCT
2. No? Observational study

For observational study the main types will then depend on the timing of the measurement of outcome, so our third question is:

Q3. When were the outcomes determined?

1. Some time after the exposure or intervention? cohort study (‘prospective study’)
2. At the same time as the exposure or intervention? cross sectional study or survey
3. Before the exposure was determined? case-control study (‘retrospective study’ based on recall of the exposure)"

Information from Spotting the Study Design, CEBM, https://www.cebm.net/2014/04/study-designs/