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Evidence Based Medicine

This page provides information on locating and evaluating literature used to support evidence based practice.

Background vs. Foreground Questions

What is the difference between a background and a foreground questions?

Background questions are more general ones that begin with how, what, why, when, or where and ask about some aspect of patient care: How do you diagnose...?  How do you treat...? What are the risk factors for…? What is the prognosis for…? With questions like this, you are not asking about specific tests, treatments, risk or prognostic factors but are more generally asking about the best among all possibilities. You are often acknowledging that you may not know a lot about a particular subject and need some general background information to get started. These are questions most appropriately answered by textbooks or online references like UpToDate or Harrison’s or the expert opinion found in general review articles. They are too general for the primary research literature to address and so aren’t good questions for a MEDLINE search.

Foreground questions, on the other hand, are more specific questions defined by the 4-part PICO acronym. They require a specific named intervention and comparison, which makes them good questions for MEDLINE and the research literature. They cover the same 4 content areas as background questions – diagnosis, treatment, etiology, and prognosis – and are the only types of questions we deal with in evidence-based medicine.

As people move through their careers, they tend to ask fewer background questions, having already acquired much of this information, and more foreground questions, which will advances their knowledge of current research in their specialty areas. 

Using PICO to Formulate Clinical Foreground Questions

PICO is a mnemonic used to describe the four elements of a good clinical question. It stands for:

P - Patient/Problem/Population
I - Intervention
C - Comparison
O - Outcome
(T) -
Time (when applicable)

For Diagnosis, you may consider using:

P - Patient
I - Test
C - Standard
O - Outcome

For Prognosis, an alternative could be:

P- Patient
I - Prognostic Factors
C - Absence of Prognostic Factor
O - Outcome (ex. Mortality)

For Risk/etiology/harm

P- Patient
I - Risk Factor
C - Absence of Risk Factor
O - Outcome

Here are links for more information.