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Evidence-Based Medicine: PICO & Question Types

PICO

P: Patient, Problem or Population What are the most important characteristics of the patient and their health status?

I: Intervention What main intervention are you considering (medical, surgical, preventative)

C: Comparison What are the alternative benchmark or goldmark standards being considered, if any?

O: Outcome What is the estimated likelihood of a clinical outcome attributable to a specific disease, condition or injury?

T: Type of Question You can have questions of different types. They can be categorized as a diagnosis, prognosis, therapy, etiology/harm, or prevention question.

T: Type of Study What study design would best answer the question: randomized controlled trial; cohort study; case controlled study; case series; case series; case report etc. See also Study Types.

 

Determine Type of Question

Type of Question Description Suggested Best Type of Study
Therapy An evaluation of a therapeutic or preventive intervention RCT>Cohort>Case Control>Case Series
Diagnosis An evaluation of a test, screening or other assessment such as history or physical exam Prospective, blind comparison to a gold standard
Prognosis An evaluation of clinical outcomes over time Cohort>Case Control>Case Series
Etiology/Harm An evaluation of a therapeutic, preventive, screening or diagnostic intervention, or a non-therapeutic exposure or behavior Cohort>Case Control>Case Series
Prevention   RCT>Cohort>Case Control>Case Series
Clinical Exam   Prospective, blind comparison to a gold standard
Cost   Economic analysis

Intervention/Therapy PICO(T)

In _____________________________________________________________ (P)how does ______________________________________________________ (I) compared to ___________________________________________________ (C) affect _________________________________________________________ (O) within _________________________________________________________ (T)?

 

Source: Stillwell SB, Fineout-Overholt E, Melnyk BM, Williamson KM. Evidence-based practice, step by step: asking the clinical question: a key step in evidence-based practice. Am J Nurs. 2010 Mar;110(3):58-61.

Etiology PICO(T)

Are __________________________________________________________ (P) who have ____________________________________________________ (I) compared with those without  __________________________________ (C) at  _________________ risk for _________________________________ (O)

over ________________________________________________________ (T)?

 

Source: Stillwell SB, Fineout-Overholt E, Melnyk BM, Williamson KM. Evidence-based practice, step by step: asking the clinical question: a key step in evidence-based practice. Am J Nurs. 2010 Mar;110(3):58-61.

Diagnosis PICO

In __________________________________________________________ (P), are/is  _____________________________________________________ (I) compared with ______________________________________________ (C) more accurate in diagnosing __________________________________ (O)?

 

Source: Stillwell SB, Fineout-Overholt E, Melnyk BM, Williamson KM. Evidence-based practice, step by step: asking the clinical question: a key step in evidence-based practice. Am J Nurs. 2010 Mar;110(3):58-61.