Lecture g

1. Life Sciences Library
Searching Resources in Evidence-
Based Medicine
Robin Featherstone, MLIS
Liaison Librarian (Medicine)
robin.featherstone@mcgill.ca
Winter 2012

2. Objectives
By the end of this lecture, you will be able to:
1. Describe the Evidence-Based Medicine (EBM)
process
2. Formulate clinical questions using PICO
3. Locate best available medical evidence
2

3. Evidence-Based Medicine: The Process
Formulating
Evaluating the clinical
the Process question
Your patient for whom
you are uncertain about
therapy, diagnosis, or Searching
Incorporating prognosis the
evidence into Evidence
decision-
making
Appraising
the Evidence
LINK
3

4. Patient Scenario
Formulate a Clinical Question
Patient, Population, or Problem
Intervention
Comparison
Outcomes

5. Patient Scenario
Clinical Scenario
You have been asked to review the practice guidelines
for treating warts. You are confident that cryotherapy
is the most effective treatment but a colleague
suggested some alternatives to investigate, including
duct tape.
Could duct tape be used for eliminating warts? Does
the literature provide evidence to support this
treatment?

6. Patient Scenario
Clinical Question
PICO
In patients with common warts, is duct tape as
effective as cryotherapy in eliminating warts?

7. What is the Evidence?
Systematic Reviews
Case-control studies
Randomized control trials
Cohort studies Case reports
Editorials
Animal research
All types of articles found in MEDLINE

8. Question Best Evidence
Cost-effectiveness •Economic analyses
Diagnosis •Diagnostic validation studies
•Prospective studies / blind comparison to a gold standard
Etiology •Randomized controlled trials
•Case-control or cohort studies
•Case series
Prevention •Randomized controlled trials
•Cohort studies, case control studies
•Systematic reviews / meta-analyses
Prognosis •Inception cohort studies
•Case control studies
•Case series
Quality of life •Qualitative studies
Therapy •Randomized controlled trials
•Systematic reviews / meta-analyses
1 Heneghan, Carl, and Douglas Badenoch. Evidence-Based Medicine Toolkit. 2nd ed. Malden, Mass.: BMJ Books/Blackwell Pub., 2006.
2 Glover, Jan, and Lei Wang. Find it Fast: The Clinical Question : www.med.yale.edu/library/education/guides/screencasts/finditfast/finditfast_2/

9. Levels of Evidence
for Therapy Question
Level of Evidence Type of Study
1a Systematic reviews of randomized controlled trials
(RCTs)
1b Individual RCTs with narrow confidence interval
2a Systematic reviews of cohort studies
2b Individual cohort studies and low-quality RCTs
3a Systematic reviews of case-control studies
3b Case-control studies
4 Case series and poor quality cohort and case-control
studies
5 Expert opinion
Levels of evidence (2001). Centre for Evidence Based Medicine. Retrieved 26 Aug 2008 from
http://www.cebm.net/index.aspx?o=1025 9

10. Information Sources
for Therapy Question
Synopsis
of
synthesis
Summaries
Filtered
1b 1a 1b 1a
2b 2a 2b 2a
Unfiltered
3b 3b
4 5 4 5

11. Criteria for Selecting an Information
Source
1. Soundness of evidence-based approach
2. Comprehensiveness and specificity
3. Ease of use
4. Availability

12. Information Sources
for Therapy Question
Filtered

13. Information Sources
for Therapy Question
Filtered

14. Information Sources
for Therapy Question
Filtered

15. Information Sources
for Therapy Question
Filtered

16. Information Sources
for Therapy Question
Filtered

17. Information Sources
for Therapy Question
Filtered
Unfiltered

18. Information Sources
for Therapy Question
Unfiltered

19. Course Website
http://www.mcgill.ca/library/library-
findinfo/courses/guides/ebm_intro/
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20. http://m.library.mcgill.ca/healthsciguide/

21. Summary Quiz
1. UpToDate is a _______ resource. And Medline is
a ________ resource.
2. The 5 stages in the EBM process are _______.
3. The best evidence to answer a therapy question
is _______.
4. To find systematic reviews of RCTs use _______.
5. To evaluate a clinical topic page, look for
_______.
LINK

22. Life Sciences Library
Questions
Robin Featherstone, MLIS
Liaison Librarian (Medicine)
robin.featherstone@mcgill.ca
Winter 2012