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Evidence-Based Medicine

Example PICO Question

In a 30-year old male patient diagnosed with depression (P), what is the effect of St. John's wort (I), as compared to SSRIs (C), on reducing depressive symptoms (O) in one year (T)?

PICO Resources

Why PICO?

The PICO format helps you

  • form an appropriate, focused question
  • identify key concepts and brainstorm search terms
  • develop a strong search strategy
  • obtain a manageable number of pertinent results
  • appraise results for relevance

Adapted from Developing a PICO Question Tutorial: Part 1 of a 2 part tutorial series from Marymount Library's PICO Tutorials. 

What is PICO?

The PICO model can help you formulate a good clinical question. Sometimes it's referred to as PICO-T, containing an optional 5th factor. 

 P - Patient,  Population, or  Problem

 What are the most important characteristics of the   patient?

 How would you describe a group of patients similar to   yours?

 I - Intervention,  Exposure,  Prognostic Factor

 What main intervention, prognostic factor, or exposure   are you considering?

 What do you want to do for the patient (prescribe a  drug, order a test, etc.)?

 C - Comparison  What is the main alternative to compare with the   intervention? 
 O - Outcome  What do you hope to accomplish, measure, improve, or   affect?
 T - Time Factor,  Type of Study  (optional)

 How would you categorize this question?

 What would be the best study design to answer this   question? 

Clinical Question Types and Study Design

Foreground questions can be further classified into four groups: therapy, diagnosis, prognosis, and etiology/harm. Certain study designs are better for answering particular question types. 

The Appropriate Study Types box lists study designs best suited to each question type, in order of utility.

 Question  Type

Definition

Appropriate Study Types

 Therapy

 Questions about the effectiveness of treatment in order   to achieve an outcome (drugs, surgical intervention,   exercise, counseling, etc.)

 Randomized   Controlled Trial   (RCT)

 Diagnosis

 Questions about identification of a disorder in a patient   presenting with specific symptoms

 RCT >

 Cohort Study

 Prognosis

 Questions about the progression of a disease or  outcome of a patient with a particular condition

 Cohort Study >

 Case Control   Studies >

 Case Series

 Etiology/Harm 

 Questions about the negative impact from an  intervention or other procedure 

 Cohort Study >

 Case Control   Studies >

 Case Series

 

Foreground and Background Questions

Clinical questions are categorized as background or foreground. Once you determine your question type, consult the box called "What Resources Should I Use?" (below) to find the appropriate resources for answering your question. 

Background Questions

  • Ask to obtain general knowledge about an illness, condition, or disease. 
  • Ask who, what, when, where, how, or why

Foreground Questions

  • Ask for specific knowledge to inform clinical decisions. 
  • Deal with specific patient or population; more complex than background questions. 

What Resources Should I Use?

For background questions:

  • Medical textbooks
  • Review articles (e.g. Annals "In the Clinic", American Family Physician, Nature Disease Primers, etc.)
  • Point of care tools and applications (e.g. DynaMed)

For foreground questions:

Asking Good Questions

According to the Centre for Evidence Based Medicine (CEBM), well-formed clinical questions are essential to practicing EBM.

"To benefit patients and clinicians, such questions need to be both directly relevant to patients' problems and phrased in ways that direct your search to relevant and precise answers." (CEBM, University of Oxford, Asking Focused Questions)