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Critical Appraisal

Information and resources on how to assess the quality and relevance of articles

PICO

PICO is a tool to assist in forming focused clinical questions. It is an acronym of:

Population - Intervention - Comparison - Outcome

By breaking down your question in this way it becomes easier to critique what you are reading.

 

Population, pathology, patient Intervention, exposure, prognosis Comparison Outcome

What are the characteristics of the population?

What is the disease or condition?

How would you describe them?

How were participants recruited / selected?

What is your treatment?

What are you observing?

What are you comparing against?

Drug, surgery, placebo, no intervention, usual care?

What are you trying to improve or measure?

What outcomes are being assessed – objective / subjective /surrogate? 

Positive outcomes - healing time, reduced infection

Negative outcomes - adverse effects, mortality

 

Example. What is the evidence for the use of intrathecal delivery of baclofen to control spasticity in cerebral palsy?

Cerebral palsy

Intrathecal pumps

Baclofen

Usual care

Muscle spasticity

You do not need to use all elements of PICO. Not all questions suit the PICO format, so there are other versions you can use.

Social interventions use PICOC:          Population - Intervention - Comparison - Outcome - Context

Restricting study types, use PICOS:    Population - Intervention - Comparison - Outcome - Study

Therapy questions use PICOT:            Population - Intervention - Comparison - Outcome - Time

 

More PICO resources

BMJ - How to clarify a clinical question.