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Research: PICO Format

PICO format

PICO is a term used to describe the four elements of a good clinical question: Patient or Problem, Intervention, Comparison, Outcome

  • Patient or Problem
    • What are the characteristics of the patient/patient group?
    • What is the condition or disease you are interested in? 
  • Intervention (or exposure)
    • Which main intervention, prognostic factor, or exposure are you considering?
  • Comparison
    • What is the alternative to the intervention (e.g., no intervention, different medication or placebo, surgery, etc.)?
  • Outcome
    • What do you hope to accomplish, measure, improve, or affect?

Question Types and Examples



Questions about the effectiveness of interventions on improving patient outcomes.

In __________ (P), how does __________ (I) compared to __________ (C) affect ____________ (O)?


What is the duration of recovery (O) for patients with total hip replacement (P) who developed a post-operative infection (I) as opposed to those who did not (C)? 


Questions about effectiveness of an intervention or exposure in preventing morbidity and mortality.

      For ________ (P), does the use of ________ (I) reduce the risk of ________ (O) compared to _______ (C)?


For adult patients in the ICU (P), do basinless baths (I) reduce the risk of acquisition of MRSA (O) compared to basin baths (C)?

In OR nurses doing a five-minute scrub (P) what are the differences in the presence and types of microbes (O) found on natural polished nails and nail beds (I) and artificial nails (C) at the time of surgery? 


Questions about the ability of a test or procedure to differentiate between those with and without a condition or disease.

In ________ (P) are/is _______(I) compared with _______(C) more accurate in diagnosing ________(O)?


In middle-aged men with suspected myocardial infarction (P), are serial 12-lead ECGs (I) compared with one initial 12-lead ECG (C) more accurate in diagnosing an acute myocardial infarction (O)?


Questions about the harmful effect of an intervention or exposure on a patient.

Are _____(P) who have _____(I) compared to those w/o_______(C) at _______ risk of _______ (O)?


Are 30- to 50-year old women (P) who have high blood pressure (I) compared with those without high blood pressure (C) at increased risk for an acute myocardial infarction (O)?


Questions about the probable cause of a patient’s disease or the likelihood that he/she will develop an illness..

In _______ (P), how does ________ (I) compared to ________ (C) influence _________ (O)? 


For patients 65 years and older (P), how does the use of an influenza vaccine (I) compared to not receiving the vaccine (C) influence the risk of developing pneumonia (O)?