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Center for Health Sciences
Medical Physiology - Evidence-Based Medicine
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What is EBM?

Patient Care Model
Life-long Learning
Why is EBM Important?
Available Evidence?
EBM Issues

The Well-built Question

The EBM Process
Anatomy of a Question

Finding Evidence

Selecting a Resource
Searching the Resource
Reviewing Search Results
Returning to the Patient

Evaluating Evidence

Evaluating the Validity
Validity Questions


Knowledge Test

Multiple Sclerosis
Case #2
Case #3
Case #4




Patient Care Model

One of the most common definitions of EBM is taken from Dr. David Sackett. Evidence-based medicine is

"the conscientious, explicit and judicious use of current best evidence in making decisions about the care of the individual patient. It means blending individual clinical expertise with the best available external clinical evidence from systematic research." (Sackett D, 1996)

EBM is the integration of these three components into the decision making process for patient care:

  • Clinical expertise - refers to the clinician's cumulated experience, education and clinical skills;
  • Patient values - bringing to the encounter his or her own personal and unique concerns, expectations, and values;
  • Best available evidence - usually found in clinically relevant research that has been conducted using sound methodology.

    (Sackett D, 2002)

Evidence, by itself, does not make a decision for you, but it can help support the patient care process. Full integration of these three components into clinical decisions enhances the opportunity for optimal clinical outcomes and quality of life.

The practice of EBM is usually triggered by patient encounters which generate questions about the:

  • Effects of therapy
  • Utility of diagnostic tests
  • Prognosis of diseases
  • Etiology of disorders

Evidence-based medicine requires new skills of the clinician, including efficiently finding evidence-based answers to specific clinical questions in point-of-care databases and the application of formal rules of evidence in evaluating the clinical literature. An additional skill is searching the voluminous primary literature index databases such as MEDLINE and PubMed when evidence cannot be found in highly approachable point-of-care databases such as DynaMed and UpToDate. Teaching this additional skill is beyond the scope of this tutorial.  

In the patient care model the EBM process can be visualized in the following steps:

The patient

1. Start with the patient - a clinical question or problem arises from the care of the patient.

The question

2. Construct a well-built clinical question from the case. 

The resource

3. Select the appropriate point-of-care resource and conduct a search.

The evaluation

4. Appraise evidence from the resource for its validity (closeness to the truth) and applicability (usefulness in clinical practice).

The patient

5. Return to the patient - integrate that evidence with clinical expertise, patient preferences and apply it to patient care.


6. Evaluate your performance with this patient.


We now go to Life Long Learning