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WHSL Asking the Clinical Question: Creating a Good Clinical Question

A guide to creating a successful search strategy for EBM searching

Analysing the Scenario

The choice of which terms to enter for your search, especially in PubMed, requires you to build what is known as a search strategy.

This entails

  • Finding the key concepts or intent of the search
  • Finding terms (eg. synonyms) for each key concept
    • Using a thesaurus such as MeSH will help to identify these synonyms, variant spellings, etc.
  • Formulating a search using Boolean logic (AND, OR)

Using the PICO formula may help to build a good search strategy

Why Use PICO?

  • To get the question clear in your mind
  • To identify the information you need to answer the question
  • To translate the question into searchable terms
  • To develop and refine your search approach 

It looks easy. It can be very tricky. It is absolutely invaluable.

Minutes spent properly formulating your question will save you hours in searching (and help you to get better marks in your IR OSCE stations!).


Constructing a Clinical Question using PICO

The PICO model will help you to construct your "foreground" clinical questions.

  • P stands for patient/population/problem or condition
  • I is the relevant intervention, exposure ot test that you want to use in relation to the patient/population or problem
  • C is the comparative (alternative) intervention, exposure or test, if there is one
  • O represents the outcome, or what you are most concerned about happening
    • Positive Outcomes: Prevention of illness or improvement in health
    • Negative Outcomes: Side effects/Adverse effects


Ben Dlamini is a 44 year old lecturer, suffering from an acute attack of pharyngitis. He has asked for a prescription for an antibiotic to treat his condition, as he is worried that he will not be able to deliver a lecture to his students and they have an important exam shortly. You need to search for the evidence as to whether this is advisable.

Using all Four Facets

Note: It is not always necessary to include all  four facets (components) in your PICO search statement, especially if you can find suitable MeSH terms to use in your search. By using prognosis in your Clinical Query search on binge drinking, for example, you will automatically include the prognosis for long-term mortalilty, as well as other outcomes. Sometimes your search will yield too few results if your search strategy is too specific.

However, you should minimally include P and I to begin with when searching under Clinical Queries in PubMed.

PICO Search Strategy

P: pharyngitis [adult]

I:  antibiotics

C: [no antibiotics]

O: [benefit/harm]