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Evidence-Based Clinical Practice Resources

This guide highlights evidence-based medicine (EBM) and evidence-based nursing (EBN) resources available at the UC Health Sciences Library.

Clinical Question

Creating a focused clinical question is a key step in EBM.

This page provides information on the EBM process, how to use PICO(TT) to form a clinical question, and the hierarchy of evidence that can be used to answer the question.

Evidence Pyramid

Evidence Pyramid

*Adapted from model used on UNC/Duke EBM Tutorial available at

EBM Process

  1. Assess the patient
  2. Ask focused clinical questions
  3. Acquire the best evidence
  4. Appraise the evidence critically
  5. Apply evidence to patient care
  6. Evaluate performance

Focused Clinical Questions & PICO(TT)

Use the PICO(TT) Format to develop specific and answerable clinical questions.

PICO description
PICO Format Definition & Questions to Consider
P Patient, Population, or Problem
What are the characteristics of the patient or population? What is the condition or disease in which you are interested?
I Intervention or Exposure
What do you want to do with this patient (e.g., treat, diagnose, observe)?
C Comparison or Intervention (if appropriate)
What is the alternative to the intervention (e.g., placebo, different drug, surgery)?
O O = Outcome
What are the relevant outcomes (e.g., morbidity, death, complications)?
T Type of Clinical Question
Diagnosis, Etiology/Harm, Therapy, Prognosis, Prevention
T Type of Study Design to Answer the Question
What would be the best study design/methodology (Systematic review, RCT, cohort study, case control, etc.)

*Descriptions from the University of Washington Evidence-Based Practice LibGuide at


Knowing the Type of Clinical Question will help you determine the best type of study design. The table* below demonstrates the types of studies generally recommended to answer particular types of clinical questions.

Clinical Question Types
Type of Question Type of Study/Methodology
Diagnosis controlled trial
Therapy double-blind RCT, Systematic review / meta-analysis
Prognosis cohort studies, case control, case series
Harm/Etiology cohort studies, case control, case series
Prevention randomized controlled trial, cohort studies
Quality improvement Randomized controlled trials

*Table adapted from

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