Skip to Main Content

Evidence-Based Practice (EBP)

Resources and Information related to the field and practice of Evidence-Based Practice (EBP)

The first step in EBP is to ask a clinical question. This is one of the most crucial steps in the EBP process as it will help you formulate your search strategy, what resources you will use, what evidence is most appropriate for your investigation, and initiate the appraisal process.

In this step, you will formulate a specific, relevant

clinical question by using the PICO method.

Click a heading to learn more about each element in the ASK process.

PICO METHOD

The PICO method is a way to help you form a specific clinical question & formulate a database search strategy. The PICO mnemonic helps you pull out the key concepts of your clinical scenario.

P: Population, Problem, Patient	How would you describe a group of patients similar to yours? What are the most important characteristics of the patient? What is the condition or disease you are interested in?
I: Intervention, Prognostic Factor, Exposure	What main intervention or exposure are you considering? What do you want to do with the patient? What is the main alternative being considered?
C: Comparison	What is the main alternative to compare with the intervention? Are you trying to decide between two drugs, etc? Can be none or placebo.
O: Outcome	What are you trying to accomplish, measure, or affect? Can be disease-centered or patient-centered.
T: Time*	How much time does it take to demonstrate the clinical outcome? How long it takes for an intervention to achieve the outcome? How long participants are observed?

* Not every question will have a time component.

FORMING THE QUESTION

After determining PICO, you can create a specific, relevant clinical question. Questions will include all the elements of PICO you identified from the clinical scenario. Everyone will "see" a different way to write out the clinical question. Below is a formula you can use to build clinical questions using PICO.

In ___ (P), what is the effect of _ (I) compared to _ (C) on _ (O) over ___ (T)*

*Remember that Time is not always necessary, often it is conveyed or understood from the question.

QUESTION TYPE/STUDY DESIGN

Clinical questions can further be classified into their domain or type, what aspect of medical care they investigate. Different types of research studies are better suited to answering questions in different domains and can help you focus your question & search strategy.

ALL CLINICAL QUESTIONS ARE BEST ANSWERED BY WELL-DONE META-ANLAYSES, SYSTEMATIC REVIEWS, OR EVIDENCE-BASED GUIDELINES.

Question Type	Best Evidence
Therapy (Treatment)	RCT
Prevention	RCT > Prospective Study
Diagnosis	RCT > Cohort Study
Prognosis (Forecast)	Cohort Study > Case-Control Study > Case Series
Etiology/Harm (Causation)	Cohort Study > Case-Control Study > Case Series
Meaning	Qualitative Studies

LEVELS OF EVIDENCE

Since some studies are better suited for answering particular questions, we can think of evidence as being arranged in a hierarchy or pyramid. Studies at the top of the evidence pyramid are more rigorous and fewer are created.

EXAMPLE

Clinical Scenario: Sheldon and Amy's baby, Kirk, as born prematurely. After speaking with other preemie parents, they are concerned about whether Kirk will be at greater risk, over his lifetime, of deafness, than full-term babies.

Elements of a Good Clinical Question	Patient/Problem/Population	Intervention/Treatment/Prognostic Factor	Comparison	Outcome
Your Case	INFANT	PREMATURE	FULL-TERM	DEAFNESS

PICO/Clinical Question: In infants, what is the effect of premature birth compared to full-term birth on deafness over the lifespan?

Domain: Prognosis

Evidence Type: Systematic Review, Meta-Analysis, Cohort Studies, Case-Control Studies