PICO questions are a kind of research question designed to conduct an evidence-based literature review or systematic review that seeks best evidence for clinical decision making.
PICO is an acronym used to describe the four concepts:
P = Patient population/problem
I = Intervention
C =Comparison
O = Outcome
(T) = Time (Optional component)
Before you start your search, it is important to have a well-built question. One way to construct a well-built question is to use the PICO model.
PICO stands for patient/population, intervention, comparison and outcomes.
Patient/Population |
Intervention |
Comparison |
Outcomes |
Who is your patient? |
What do you plan on doing for the patient? |
What alternative are you considering? |
What do wish to accomplish? |
Age, sex, race or patient Primary problem Health status |
Diagnostic test Medication Procedure |
Another test, medication or procedure Watchful waiting |
Accurate diagnosis Relieve or improve symptoms Maintain function |
How would you describe a group of patients similar to yours? What are the most important characteristics of the patient? |
What main intervention, exposure, or prognostic factor are you considering? What do you want to do with this patient? |
What is the main alternative being considered, if any? |
What are you trying to accomplish, measure, improve or affect? |
The PICO framework can be used to break down various types of questions into their component parts:
Question Type |
P |
I |
C |
O |
Therapy |
Patient characteristics, disease |
Specific drug or procedural intervention |
Comparison intervention (e.g., placebo or no treatment) |
Outcomes of interest (e.g., management of diseases or condition) |
Etiology |
Patient or population |
Exposure to certain conditions or risk behaviours |
Absence of certain conditions or risk behaviours |
Outcomes of interest (e.g., development of disease or condition) |
Diagnosis |
Patient or problem |
Specific diagnostic tool or procedure |
Alternative diagnostic tool or procedure (e.g., current gold standard) |
Specificity, sensitivity (usually left blank in a search) |
Prognosis |
Patient, population, or problem |
Prognostic factor |
None |
Outcomes of interest (e.g., morality. recurrence) |
Question Type |
Patient or Problem |
Intervention or Exposure |
Outcome |
Comparison |
Therapy |
In patients with hypertension and at least one additional cardiovascular disease risk factor |
Does tight systolic blood pressure control |
Lead to lower rates of myocardial infarction, stroke, heart failure, and cardiovascular mortality |
Compared to conservative control? |
Diagnosis |
Among asymptomatic adults at low risk of colon cancer |
Is fecal immunochemical testing (FIT) |
As sensitive and specific for diagnosing colon cancer |
As colonoscopy? |
Prognosis |
Among adults with pneumonia |
Do those with chronic kidney disease (CKD) |
Have a higher mortality rate |
Than those without CKD? |
Etiology or Harm |
Are women |
With a history of pelvic inflammatory disease (PID) |
At higher risk for gynecological cancers |
Than women with no history of PID? |
Prevention |
Among adults with a history of myocardial infarction |
Does adherence to a Mediterranean diet |
Lower risk of a second myocardial infarction |
Compared to those who do not adopt a Mediterranean diet? |
Fill in the blanks with information from your clinical scenario:
THERAPY
In_______________, what is the effect of ________________on _______________ compared with _________________?
PREVENTION
For ___________ does the use of _________________ reduce the future risk of ____________ compared with ______________?
DIAGNOSIS OR DIAGNOSTIC TEST
Are (Is) ________________ more accurate in diagnosing _______________ compared with ____________?
PROGNOSIS
Does ____________ influence ______________ in patients who have _____________?
ETIOLOGY
Are ______________ who have _______________ at ______________ risk for/of ____________ compared with _____________
with/without______________?
MEANING
How do _______________ diagnosed with _______________ perceive __________________?
Melnyk, B. M., & Fineout-Overholt, E. (2011). Evidence-based practice in nursing & healthcare: A guide to best practice. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins.
Approach 1: Horizontal Searching of each concept using OR combined with Vertical Search of AND
Approach 2: Vertical Search each concept followed by Search History
Vertical search concept synonyms example:
Use Search History to combine search results for individual concepts:
Many databases use specific vocabulary to represent concepts. This is called controlled vocabulary or subject headings. MeSH terms are a kind of Medical Subject Heading used in Medline.
To search for subject headings related to your concept in Medline:
A list of related subject terms will appear. Check the Scope Note to be sure the definition relates to your concept!
The following two videos, although targeted toward a nursing audience, give excellent summaries of how to formulate your PICO question and then, how to use your PICO question to search library databases. Just substitute the word nursing for dental hygiene or the CINAHL database for Medline!