a Good Question (PICO)
the right question is a difficult skill to learn, yet it is fundamental
to the evidence-based decision-making process. This process almost always
begins with a patient question or problem. A "well-built" question should
include four parts, referred to as PICO that identify the patient
problem or population (P), intervention (I), comparison
(C) and outcome(s) (O). 1
The first step in developing
a well-built question is to identify the patient problem
or population. Describe either the patient's chief complaint or generalize
the patient's condition to a larger population.
When identifying the P in
PICO it is helpful to ask:
How could you describe a
group with a similar problem?
How you would describe the patient to a colleague?
What are the important characteristics of this patient?
- Primary Problem
- Patient's main concern
or chief complaint
- Disease or health status
- Age, Race, Sex, Previous
ailments, current medications
Should these characteristics
be considered as I search for evidence? 1
The P phrase could
be more detailed if the added information influences the results you expect
the Intervention is the second step in the PICO process. It is
important to identify what you plan to do for that patient. This
may include the use of a specific diagnostic test, treatment, adjunctive
therapy, medication or the recommendation to the patient to use a product
or procedure. The intervention is the main consideration for that patient
or client. 1
The Comparison is the third phase of the well-built
question, which is the main alternative you are considering.1
It should be specific and limited to one alternative choice in order to
facilitate an effective computerized search.
The Comparison is the only optional component in the PICO question. One
may only look at the Intervention without exploring alternatives, and
in some cases, there may not be an alternative.
The Outcome is the final aspect of the PICO
question. It specifies
the result(s) of what you plan to accomplish, improve or affect and should
be measurable. Outcomes may consist of:
relieving or eliminating
improving or maintaining function
or enhancing esthetics.
Specific outcomes will yield
better search results and allow you to find the studies that focus on
the outcomes you are searching for. When defining the outcome, more
effective is not acceptable unless it describes how
the intervention is more effective.
For example, more effective
in preventing caries, or in decreasing probing depths.
In addition to identifying
the PICO components, it is important to clarify the type of question you
are asking and the related research method. The categories for types of
Based on four PICO component,
a final PICO question can be stated as:
For a patient with Tetracycline staining, will chairside (ZOOM) bleaching
as compared to over the counter White Stips decrease staining and increase
Once you have identified a patient problem and defined your question using
PICO, you are ready to find the most current valid evidence.
Worksheet and Search Strategy provides the framework for developing
this step of the process by guiding one to write each component of the
PICO question and is also a
guide in developing a search strategy, which aids
in the retrieval of relevant clinical evidence.
Conducting a computerized search
with maximum efficiency to answer the question is the second step in the
to PICO Resources
to Searching Basics
- Sackett DL, Richardson
WS, Rosenberg W, Haynes RB (1997). Evidence-based medicine: How to
practice and teach EBM. New York: Churchill Livingston.