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Ask a clear, answerable
question.
The first critical step is to clarify one or two key issues
that come up in the course of caring for your patient and to develop a focused
clinical question.
Without this crucial step, the rest of the steps are
immaterial. |
A well-built clinical
question has four components. The mnemonic PICO is useful for
remembering these.
- Patient or Population -- Be specific about the group you are
interested in. Consider age, sex, risk profile, or other traits that may be
clinically relevant.
-
Intervention -- Again, be specific
about the intervention (or exposure) you are looking for (e.g., treatment with
inhaled corticosteroids, passive smoking, surgical procedure)
- Comparison Intervention -- What alternatives do you
want to compare the intervention to (e.g., standard therapy for asthma, chest
x-ray, watchful waiting)
- Outcome -- Try to be precise, yet brief,
in defining the outcome (e.g. growth delay, diagnostic usefulness)
In addition to the PICO
model, there are a number of variations, one of which is PICOTT. This model
reflects that the type of question you are asking will yield various study
types.
- T -- What type of question are you asking?
Therapy/Treatment, Diagnosis, Prognosis, Harm/Etiology, Prevention, Quality
Improvement.
- T -- What type of study do you want to find? What would be
the best study design/methodology?
| Type of Question/Domain |
Type of Study/Methodology |
Therapy/Treatment
Selection of
treatments or interventions that do more good than harm and that are worth the
effort and cost.
|
Double-Blind Randomized Controlled Trial
Systematic
Review/Meta Analysis |
Diagnosis
Selection and
interpretation of diagnostic tests, in order to confirm or exclude a diagnosis,
based on considering their precision, accuracy, acceptability, expense, safety,
etc.
|
Randomized
Controlled Trial
Systematic Review/Meta Analysis |
Prognosis
Estimation of a
patient's likely clinical course over time and anticipation of likely
complications of disease.
|
Cohort
Study
Case Controlled Study
Case Series |
Harm/Etiology
Identification of
causes or risk factors for disease.
|
Cohort
Studies |
Prevention
|
Randomized
Controlled Trial
Cohort Studies |
| Quality Improvement |
Randomized
Controlled Trials |
EXAMPLE
QUESTION 1
In elderly patients, are ACE inhibitors
more effective than beta blockers in controlling high blood pressure and
minimizing adverse effects?
The
“Population” is elderly patients, the “Intervention” is ACE
inhibitors, the “Comparison Intervention” is beta blockers, and the
“Outcome” is controlling high blood pressure and minimizing adverse
effects.
EXAMPLE QUESTION 2
In children with asthma, are inhaled steroids more likely to
result in growth delay than standard therapy with
beta-agonists
The “Population” is
children with asthma, the “Intervention” is inhaled steroids, the
“Comparison Intervention” is beta-agonists and the
“Outcome” is growth delay. |
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