Skip to Main Content

Evidence Based Practice: Ask

Resources, tips, and tools for evidence-based practice in health care

Ask a focused question

Ask an answerable clinical question

According to the Centre for Evidence Based Medicine (CEBM), well-formed clinical questions are essential in practicing EBM. "To benefit patients and clinicians, such questions need to be both directly relevant to patients' problems and phrased in ways that direct your search to relevant and precise answers." - CEBM, University of Oxford, Asking Focused Questions

Define the question to be answered using the PICO model.

Use PICO to Create a Search Strategy

The PICO model:

Ask a clinical question using PICO model,

P = Patient / Population / Problem

I = Intervention / Indicator / Exposure

C = Comparison / Control

O = Outcome

(T/M/S = Type of Study / Time element / Methodology / Setting) Optional

The PICO model allows you to formulate an answerable question.


EHSL Worksheets:


Tutorials on PICO:

Types of Questions & Types of Studies

There are several types of research questions which lend themselves to types of studies.

  • Etiology / Harm: identifying associations, risk factors and causes of a disease
  • Diagnosis: selecting tests that accurately detect a disease
  • Therapy / Prevention: selecting effective interventions to treat or prevent a disease
  • Prognosis: predicting the probable outcome of a disease or treatment
Type of Question Type of Study
Therapy RCT | Cohort Study
Diagnosis Prospective, blind controlled trial comparison to gold standard
Prevention RCT | Cohort Study | Case Control
Prognosis Cohort Study | Case Control | Case Series/Case Report
Etiology / Harm Cohort Study | Case Control | Case Series
Cost analysis economic analysis
   Note:  Meta-analyses and systematic reviews, when available, often provide the best answers to clinical questions

Pyramid of Evidence

The pyramid of evidence illustrates the hierarchy of literature and evidence.

Pyramid of Evidence. Dartmouth College and Yale University

Get help! Request a consultation

Ask a Question

Need Full Text?

Look for this button to link to full text options:

Find It icon which links to full text from U Libraries licensed databases.