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Evidence-based Practice in Healthcare

This guide is designed to assist health care professionals and students become effective and efficient users of the medical literature.

The PICO Model

What is the PICO model?

A model to help define a clinical question in terms of the specific patient/population/problem. The PICO  model aids the searcher (you) in finding clinically relevant evidence in the literature in an organized way.

PICO(s) chart. P - patient/problem. I - intervention. C- comparison. O- outcome. S- study type.

When to use the PICO model-

Background questions concern general knowledge.   These types of questions generally have only two parts:

  1. A question root (who, what, when, where, how, why)
  2. A disorder, test, treatment, or other aspect of health care 

Often these questions can best be answered by using a textbook or consulting a clinical database.

Foreground questions are specific knowledge questions that affect clinical decisions, including a broad range of biologic, psychological, and sociologic issues.  These are the questions that generally require a search of the primary medical literature and that are best suited to the PICO format.

PICO Model for Clinical Questions

P Patient, Population, or Problem  How would I describe a group of patients similar to mine? 
I Intervention, Prognostic Factor, or Exposure  Which main intervention, prognostic factor,
or exposure am I considering?
C Comparison or Intervention (if appropriate)  What is the main alternative to compare
with the intervention?
O Outcome you would like to measure or achieve What can I hope to accomplish, measure,
improve, or affect?
T Time Over what period of time?
S Type of study you want to find

What would be the best study design/methodology?

Table based on: Evidence Based Medicine: PICO. UIC Library.