Finding the Evidence

Trina FyfeHealth Sciences Librarian, UNBC-NMP

Phone: 960-5195fyfet@unbc.ca

http://web.unbc.ca/~fyfet/index.html

ObjectivesThe overall objectives for the modules are to learn how to find evidence

using electronic resources and be able to:

• Understand how searching fits into Evidence Based Clinical Practice.

• Identify foreground and background literature.

• Formulate searchable questions using PICO.

• Identify appropriate electronic resources available (licensed and free),

• the strengths and weakness of each, and when to use them.

• Feel comfortable searching electronic resources covered in these modules.

Components of a well-built question

Patient

Population

Problem

What group do you want information on? Be Specific!

Intervention

(or exposure)

What intervention (or prognostic factor or treatment or exposure) do you want to consider?

Comparison Compared to what? Better or worse than no intervention at all, or better than another intervention?

Outcomes What is the effect of the intervention?

Background vs. Foreground

Background

• General questions about conditions, illnesses, syndromes and patterns of disease, and pathophysiology; such as "What is the typical clinical presentation of Parkinson's disease?"

• Resources: evidence based textbooks and reviews

http://www.med.ualberta.ca/ebm/ebmintro.htm

Background vs. ForegroundForeground

• Questions are more often about issues of care

• Knowledge needed for specific and relevant clinical decision-making

• Questions are often complicated. Breaking it down into components will help build a searchable foreground question: "PICO“.

• Resources: guidelines, systematic reviews, or some evidence-linked textbooks, and may also include the primary literature

http://www.med.ualberta.ca/ebm/ebmintro.htm

Levels of Evidence

• Oxford Centre for Evidence-based Medicine Levels of Evidence (May 2001)

• The Evidence Pyramid

• "4S" levels of organisation of evidence from research (next slide)

Copyright ©2001 BMJ Publishing Group Ltd.

Haynes, R B. Evid Based Med 2001;6:36-38

Figure "4S" levels of organisation of evidence from research.

Type of Clinical Question Type of Quality Filter

Therapy Randomized Controlled Trial

Diagnosis Controlled Trial

Prognosis Cohort Studies,Case Control,Case Series

Etiology/Harm Cohort Studies

http://www.uic.edu/depts/lib/lhsp/resources/levels.shtml

Type of question

Clinical Query

A 3yr old boy is brought to the Emergency Department suffering gastroenteritis. You estimate him to be suffering from moderate (5-10%) dehydration, and feel he needs rehydrating. Aware that he does not want to take oral fluids, and is likely to vomit these back anyway, you wonder whether IVT would be a satisfactory alternative. (bestbets)

PICO

Patient

Population

Problem

Intervention

(or exposure)

Comparison

Outcomes