Basics of Evidence-based Medicine Literature Searching

1. Introduction to EBM
Resources
Dr. Imad Salah Ahmed Hassan MD (UK) FACP FRCPI MSc MBBS
Consultant Physician & Pulmonologist
Chairman, Knowledge Translation Committee
Department of Medicine
KAMC
Riyadh
Kingdom of Saudi Arabia
imadsahassan@gmail.com

2. What is Evidence-based
Medicine

“ Evidence-based medicine is the

integration of:
 best available research evidence with
 clinical expertise and
 patient values”

Sackett, et al 2001

3. Three Pronged Approach
The
Patient
Patient’s characteristics,
preferences & values
EBP!
Best
Evidence
Clinically relevant research,
the literature
Clinical
Expertise
3
Practitioner’s knowledge
& experience
3

4. Integrates Evidence With

Clinical expertise

Experience

Judgment

Patient values and preferences

Quality of life

Costs

Other important factors

5. Patient Values
and
Preferences
Clinical
Expertise
Best
Available
Evidence
Quality
of Life
Cost/
Availability

6. What is Evidence-based
Practice
EBP is about asking questions and
searching for answers in the body of
medical research, and having found a likely
source of information appraising the paper
for its scientific validity and then applying
the result to your problem.

7. Evidence-based Practice
Ask clinical
Acquire the
Questions
best evidence
Assess
5A’s !!
Appraise
effectiveness,
efficiency of EBM
process
the evidence
Apply
evidence to
your patient

8. Evidence-based Practice
Acquire the
Ask clinical
best evidence:
Literature Searching
Questions: PICO
Assess
5A’s !!
effectiveness,
efficiency of EBM
process
Appraise
the evidence:
Critical Appraisal
Apply
evidence to
your patient:
Knowledge Translation
(Implementation)

9. Self-Education & Training in
EBM

EBM Resources:



CEBM Website:



http://guides.mclibrary.duke.edu/content.php?pid=
274373&sid=2262393
http://www.med.yale.edu/library/education/guides/
feature/finditfast
http://www.youtube.com/user/cebmed,
http://www.cebm.net/index.aspx?o=1965
YouTube:

http://www.youtube.com/watch?v=odfo9CQGi0c

11. Objectives

Why do Healthcare Professionals need to be
competent in Literature Searching?

Who should be competent in Literature
Searching?

Prerequisites for completing a successful
Literature Searching exercise.

12. Rule 31 –
Review the World Literature Fortnightly*
*"Kill as Few Patients as Possible" - Oscar London
Medical Articles per Year
2500000
5,000?
per day
2000000
1500000
1000000
55 per
day
1,400 per
day
500000
0
Trials
MEDLINE
BioMedical

13. The Decline in Knowledge and Patient
Outcomes

14. Competency in Literature
Searching for Professionals




Dealing with the daily “challenge” to one’s
knowledge.
Life-long learning.
Evidence-based practice
Valuable employee.

15. For
Whom?

16. Chairman
Resident
Quality
Nursing
Manager
Clinical
Director
Nurse

17. Competency in Literature
Searching: For Whom?
Healthcare
Professionals Including
Policymakers etc
 Patients!


18. Competency in Literature
Searching for Patients

For successful incorporation of:


1. Values and Preferences
2. Patient-centered Care

19. The 6 Prerequisites for
successful Literature Searching
1
2
3
4
5
6
• Know how to use a computer/electronic device.
• Know the Internet Jargon of Terms.
• Know the EBM Jargon of Terms.
• Know how to formulate your question.
• Know where to go.
• Know what to do when you get there: the site’s technical
language/know-how.

20. Know how to use a
computer/electronic
device.

21. Prerequisites for successful
Literature Searching

Know how to use a computer/electronic
device.
Computer Literacy

22. Prerequisites for successful
Literature Searching

Know the Internet Jargon of Terms e.g.




What is a Website?
What is a Database?
What is a Search Engine?
What is a Meta-search Engine?

23. What is a Website?
• An internet site and an information resource on the
World Wide Web. Websites may provide information
on any topic.
• A collection of files that are arranged on the World
Wide Web under a common address and allows
retrieval via a browser.
• Examples: Pubmed, Yahoo, Guidelines Websites etc

25. What is a Database?
• A Database is an organized collection of information
records that can be accessed electronically e.g.
Medline (Pubmed), Cochrane etc

27. What is a Search
Engine?
• A web-based computer-program that allows users to
electronically search and retrieve specific information
online.
• It searches documents and databases for specified
keywords and returns a list of the documents where the
keywords were found.
• Internet search engines help users find web pages on a
given subject.
• General: e.g. Google, Yahoo etc
• Specialized: Google Scholar, Pubmed

30. What is a Meta-search Engine?
• A search engine that queries other search engines
and then combines the results that are received from
all.
• In effect, the user is not using just one search engine
but a combination of many search engines at once to
optimize Web searching.
• General: dogpile
• Specialized: TRIP, SumSearch.

32. “turning research into practice”

34. Prerequisites for successful
Literature Searching

Know the EBM Jargon of Terms.

35. EBM Terminology
• Knowledge: Foreground/Background
• Types of Literature Articles: Primary
(Original)/Secondary (Pre-appraised)
• Clinical Outcomes: Patient-oriented vs Disease
Oriented Outcomes
• Reviews: Systematic/Non-systematic (Narrative)
• CAT: Critically Appraised Topic
• Clinical Practice Guidelines
• Levels of Evidence: Hierarchy Pyramid
• Sources of Evidence: Point-of-care etc
• Knowledge Translation Resources

36. Ask clinical question
Background /Foreground questions
•
Background Question
•
Asks for general knowledge about a disorder. Textbooks
are good for answering background questions
•
Foreground Question
Asks for specific knowledge about managing patients
with a disorder; consists of three or four components
(PICO): Diagnosis, Therapy, Prognosis etc
Journal articles are good for answering foreground
questions.

37. Background versus Foreground
Information

Case discussion: 27 year old woman with right lower
quadrant (RLQ) abdominal pain

Background information available from textbooks

What is the clinical course/complications of the different
diagnoses


What typically presents as RLQ pain
Specifically, what is typical presentation of appendicitis
Foreground information

How good is a CT scan for appendicitis?

38. Ask clinical question
Foreground
questions
Background
question
novice
expert

39. Types of Literature

Primary (Original)

Secondary (Pre-appraised)

40. Types of Literature

Primary (Original)

Research publications e.g. in



Pubmed
Embase
CINAHL

41. The Pre-appraised Literature
• Pre-appraised = The Secondary Literature
• Useful for point-of-care searches
• Databases with pre-appraised evidence will give you
the highest quality information in the shortest amount
of time.
• Two types of pre-appraised databases
– Those with pre-appraised Synthesis of studies e.g.
Guidelines and Systematic Reviews
– Those with pre-appraised Individual studies:
Critically appraised Topics CATs

42. Important Outcomes

Patient Oriented Outcomes: PO Evidence
outcomes patients actually care about




Death (overall or disease-specific)
Heart attacks, strokes, amputations, bed sores, broken hips,
renal failure, etc.
Ability to perform activities of daily living
Versus
Disease oriented outcomes: DO Evidence

Biochemical, physiologic, pharmacologic, or laboratory
measures

43. Comparing DOE and POE
Example
DiseaseOriented
Evidence
Patient-Oriented
Evidence that
Matters
Comment
Anti-arrhythmic
Therapy
Drug X  PVCs
on ECG
Drug X increases
mortality
POE contradicts
DOE
Type 2 Diabetes
Aggressive Tx
with insulin or
oral agents
can keep BS low
Aggressive Tx
does not reduce
mortality or
prevent most
complications
POE contradicts
standard teaching
Prostate
Screening
PSA screening
detects prostate
cancer early
Does PSA
screening 
mortality?
DOE exists, but
POE is unknown
Shaughnessy AF, Slawson DC. Getting the Most from Review Articles: A Guide for
Readers and Writers. American Family Physician 1997 (May 1);55:2155-60.

44. What is a Systematic
Review?
What is a Systematic Review?
• Systematic Reviews (SRs)
– Use a systematic methodology to identify, critically
appraise, and synthesize relevant studies
– Individual studies assessed for validity
– Differ from traditional review articles (Narrative
Reviews) in that conclusions are evidence-based
rather than commentary

45. Comparison Chart
Systematic vs. Narrative Review
Systematic Review Article
Narrow focus, answers foreground
questions
Systematic scientific approach to
finding, evaluating and
summarizing the evidence
Review Article
Broad focus, answers background
questions
Depends on the author’s inclination
Comprehensive search for relevant
articles
Author gets to pick using any criteria
Explicit methods of appraisal and
synthesis
Methods usually not specified
Meta-analysis may be used to
combine data
Vote count or narrative summary

46. What is a Meta-analysis?
• Meta-analyses
– Uses studies from a Systematic Review and
applies statistical techniques for combining
quantitative data.
– A systematic review that uses quantitative
methods to summarize the results.

47. Evidence-based Practice Guidelines
• Systematically gather and “grade” evidence on a topic
• Developed by professional groups, government
agencies, local practices etc

48. What is a Clinical Practice Guideline?

49. Level of evidence/Grades of
Recommendations
Grades of
Recommendations
Validity/Strength of Inference
Oxford Centre of EBM
Ia
Systematic reviews (meta-analyses) of RCTs
Ib
Randomized controlled trials
Bias
II
Cohort studies
III
Case-control-studies
IV
Case-series
V
Expert opinion
Bias
Bias
Bias
Bias
Bias

50. What is Critical Appraisal?



Critical Appraisal:
The process of assessing and interpreting the
evidence by systematically considering its
validity, results and relevance to the area of
work considered.
It answers 3 important questions: How well is
this study performed? What does it show? Can I
use it?

51. Critically-Appraised Topic (CAT):
What is a Critically Appraisal Topic?
A standardized one-page summary of the
evidence.
It consists of a declarative title, clinical bottom line,
the clinical question (PICO), search terms, a
summary of the study methods, a table
summarizing the key results and additional
comments (Sackett).

52. What is the Best Evidence? Hierarchy of
Levels of Evidence

53. Randomized Controlled Clinical Trial
(RCT)
What is a Randomised Controlled Trial?
A group of patients is randomized into an
experimental group and a control group. These
groups are followed up for the variables/outcomes of
interest.

54. Prerequisites for successful
Literature Searching

Know how to formulate your question.

55. Evidence-based Practice
Ask clinical
Acquire the
questions
best evidence
Assess
5A’s !!
Appraise
effectiveness,
efficiency of EBM
process
the evidence
Apply
evidence to
Your patient

56. Evidence-based Practice
Ask clinical
questions
PICO
Ask: Refine ability to convert need for information (e.g.,
therapy, prevention, diagnosis, prognosis) into an
answerable question.
PICO format for foreground questions.

57. Ask clinical question

58. Ask Clinical Questions: PICO
Components of Clinical Questions
Patient/
Population
Intervention/
Exposure
Comparison
Outcome
does early treatment with a statin
compared to
placebo
decrease cardiovascular mortality?
In women with
suspected
coronary disease
what is the
accuracy of
exercise ECHO
compared to
exercise
ECG
for diagnosing
significant
CAD?
In postmenopausal
women
does hormone
replacement
therapy
compared to no
HRT
increase the
risk of
breast cancer?
In patients with
acute MI

59. Prerequisites for successful
Literature Searching

Know where to go.

60. Evidence-based Practice
Acquire the
best evidence
Literature
Search
Acquire: Select “best evidence” resources to answer clinical
questions using criteria of:
Validity – Can I trust the evidence?
Relevance – Does the evidence apply to my patient?
Time efficiency – Can I get the evidence fast?

61. Types of Resources

62. Characteristics of a Good
Resource

63. “Finding Evidence”: Sources

Primary: PubMed, EmBase, Cinahl, Pyschlit

64. Primary Resources

65. Primary Resources

66. “Finding Evidence”: Sources





Secondary:
Systematic Reviews: Cochrane Library, PubMed
Guidelines websites: Guidelines Clearinghouse, Guidelines
International Network
CATS: BestBets, ACP Journal Club
Point of Care: Clinical Evidence, EvidencePlus, UpToDate etc

67. Secondary Resources

68. Secondary Resources

69. Secondary Resources

70. “Finding Evidence”: Sources

Tertiary resources (meta search engines, databases of
databases):

TRIP+ (Translating Research Into Practice)

SumSearch

71. Tertiary Resources

72. Know what to do when you
get there: the site’s technical
language/know-how.

75. Resources For EBM Knowledge Translation
EBM Hunting Tools
EBM Resources
Advanced EBM Skills
Point of Care
Clinical
Resources
Updates
New Evidence
Decision
Support
Systems
Critical
Appraisal
Tools
EvidenceBased
Guidelines &
Policies
EvidenceBased Quality
Improvement
•DynaMed
•Essential
Evidence Plus
•First Consult
•UpToDate
•Clinical
Evidence
•ACP PIERS
•Mc Master
Plus: STAT
REF
•BMJ
Evidence
Updates/Alerts
•ACP Journal
Club
•Open Clinical
•Dxplain
•Emergency
Medicine on
the Web
•Clinical
Decision
Making
Calculators
•EBM toolbox
•CATmaker
•Evidence
based
medicine
toolkit
•EBM
Calculator
•National
Guidelines
Clearinghouse
• NHS
Evidence
• ICSI Institute
for Clinical
Systems
Improvements
•AHRQ
•Institute for
Healthcare
Improvement
•Knowledge
Translation
Clearinghouse
•NICE

77. Types of Resources
1.
2.
3.
4.
5.
6.
7.
8.
Point of Care Clinical Resources/Decision
Support Systems
Up-Dates & New Evidence
Evidence-Based Guidelines, Policies and
Protocols
Evidence-Based Quality Improvement
Critical Appraisal Tools
EBM Audiovisual Training
Innovations Exchange for New Ideas of Care
Portals to All

78. Resources For EBM Literature
Searching
1
2
3
4
• Point of Care Clinical
Resources/Decision Support Systems
• Up-Dates & New Evidence
• Evidence-Based Guidelines, Policies
Pathways and Protocols
• Evidence-Based Quality Improvement

79. Resources For EBM Literature
Searching
5
6
7
8
• Critical Appraisal Tools
• EBM Audiovisual Training
• Innovations Exchange for New
Ideas of Care
• Portals to All

80. 5S Information Resources: Information in top 4 are used
Computerized Decision
Support System (CDSS)
Systems
Evidence based textbooks : UpTo
POCRaTs
Summaries
Date, DynaMed, ACP PIER, BMJ Clinical
Evidence
Evidence based journals
Synopses
EBM, EBN, EBMH, ACP J club
Systematic Review
Syntheses
Cochrane reviews
Original articles:
BMJUpdates, PubMed
Clinical Queries
Studies
2009
NCKUFM-YCY
Haynes, R. (2006, November). Of studies, syntheses, synopses, summaries, and systems: the 5S evolution of information services for
evidence-based health care decisions. ACP Journal Club, 145(3), A8-A9.