Concise explaining of Evidence-Based Medicine and discussing the following: 1-What is Evidence-Based Medicine? 2-Why Evidence-based Medicine? 3-Options for changing clinicians' practice behaviour 4- EBM Process- Five Steps 5-Seven alternatives to evidence-based medicine

2. Evidence Based Medicine
Dr. MOHAMMAD VAZIRI-Thoracic Surgeon
Iran University of Medical Sciences
Member of The
New York Academy of Sciences
European Society of Thoracic Surgeons
International Association for the Study of Lung Cancer
European Society of Medical Oncology
Clinical Research Associate – McMaster University

3. Evidence Based Medicine-Outline
1-What is Evidence-Based Medicine?
2-Why Evidence-based Medicine?
3-Options for changing clinicians' practice behavior
4- EBM Process- Five Steps
5-Seven alternatives to evidence based medicine

4. What is Evidence-Based Medicine?
The practice of EBM is the integration of
• Individual clinical expertise
• Best available clinical evidence from systematic
search.
• Patient’s values and expectations

5. Individual Clinical Expertise:
• Clinical skills
• Clinical judgment :Vital for determining whether
the evidence applies to the individual patient at
all and, if so, how
• EBM is meant to complement, not replace, clinical
judgment in tailoring care to individual patients

6. Best External Evidence:
• From real clinical research among intact
patients.
• Has a short doubling-time (10 years).
• Replaces currently accepted diagnostic tests and
treatments with new ones that are more
powerful, more accurate, more efficacious, and
safer.

7. A model for evidence-based clinical decisions

9. Conventional medicine
experiences
Pathophysiology,
references,…
Patient value

10. EBM process
• POEM: Patient Oriented Evidence that Matters
Conventional medicine
• DOE: Disease Oriented Evidence

11. • A BRIEF HISTORY
• 1980’s: McMasters University in Ontario, Canada
• Dr. David Sackett and colleagues proposed Evidence Based
Medicine (EBM) as a new way of teaching, learning and
practicing medicine.
• Dr. Sackett defines EBM as:
“…The conscientious, explicit, and judicious use of current best
evidence in making decisions about the care of individual patients.”

12. • Why Evidence-based Medicine?
• Physicians have daily need for valid information
• Traditional sources of information shortcomings:
Textbooks :partially (10-30%) outdated before
publication
Experts: biased towards their own works & knowledge
CME: ineffective
Medical Journals: too voluminous
• Clinical judgment / diagnostic skills increase with time,
but up-to-date clinical knowledge declines

13. • Reference-based medicine shortcomings:
• First, idea second, references
• Vague questions
• Systematic search is not usual
• Critical appraisal is not usual
• Inadequate evaluation

14. • The value of EBM is heightened in light of the following
considerations:
●The volume of evidence available to guide clinical decisions
continues to grow at a rapid pace .
●Improvements in research design, and methods for analyzing data
have led to a better understanding of how to produce valid clinical
research.
●Many published study results are false or draw misleading
conclusions.
●Many clinicians, do not practice medicine according to the best
current research evidence

15. Evidence Based Medicine
It is a change in the way physicians practice medicine, teach and
learn, and handle research.
Clinical practice: Based on the best current evidence
(not necessarily on how it’s always been done)
Patient Care: Compassionate, patient-oriented
(less authoritarian)
Learning & Teaching: Problem-based, problem-solving
more investigative, less know-it-all-by-yesterday
Research: More stringent approach, better proof criteria
(more demanding of proof, less room for error)

16. • The database of MEDLINE has
approximately 24 million references
from more than 4000 journals with
more than 400000 new entries added
each year.
Why Is It So Hard to Be Up-to-date?

18. • (Panel A) Total number of new publications
listed in MEDLINE by year.
• (Panel B) Number of publications of
randomized trials listed in MEDLINE by year

19. Washington
Monument
A Year of MEDLINE
indexed journals
555 feet

20. How many original articles should a
specialist read each week to remain
up to date in his/her own field only ?
 5
 10
 20
 40
 100
The story is different for a generalist: 17 /day!
Dr.S.Naserimoghaddam

21. Our textbooks are out-of-date
• Fail to recommend Rx up to ten years after it’s
been shown to be efficacious.
• Continue to recommend therapy up to ten
years after it’s been shown to be useless.
Antman EM, Lau J, Kupelnick B, Mosteller F, Chalmers TC: A comparison of results of
meta-analyses of randomised control trials and recommendations of clinical experts. JAMA 1992;268:240-8

22. • The goal of information mastery is to determine the
information source with the highest usefulness score
A Useful Equation!

23. The Slippery Slope
years since
graduation
r = -0.54
p<0.001
...
...
. ..
. . .... .
....
....
...
..
...
knowledge
of current
best care

24. Does CME Work?
– Traditional CME in a nice place is
unfortunately completely ineffective
in changing our behavior.

25. • Use of drains
• Antibiotic prophylaxis
• Use of subcutaneous heparin to prevent
thromboembolic complications of an operation.
Indeed, no one could pass the “Principles of
Surgery” examination before board certification
without knowledge of these three data sets.

26. • Despite everyone knowing how best to use the
evidence on these three issues, Wasey and
coworkers have demonstrated clearly on a
colorectal service.
• Overuse of drains
• Underuse of heparin
• Misuse of antibiotics

27. • Recent systemic reviews and meta-analysis of
the use of drains in abdominal surgery and of
nasogastric tubes in general surgery have
confirmed:
Absence of patient benefit and the possibility of
harm.
Yet a tour on any general surgical floor and some
others will confirm that both abdominal drains
and nasogastric tubes are in common use. Why?

28. • Grand Canyon: a deep gorge about 44- km long
formed by the Colorado River in Arizona, USA.
It is 8–24 km wide, in places 1800 m deep.
• —Oxford Encyclopaedia.
• The gap between what we know and what we do
yawns like the Grand Canyon, but it can and must
be bridged.

29. • A major driver for variations in clinical practice relates
to the surgical training structure
which is essentially an apprentice-based approach
surgical trainees are expected to practice in the model of
their teachers.

30. • Health care requires Revolution, not
reorganization
• Transformation, not reformation.
Change is hard; changing a professional's practice
is really hard.

31. • Approaches to health care
• Current
New
• Care based on visits
Care based on continuous healing
• Professional autonomy drives variability
Care is customized according to patients' needs
and values
• Professionals control care
The patient is the source of control
• Information is a record
Knowledge is shared freely

32. • Approaches to health care
• Current
New
• Decision-making is based on experience and training
Decision-making is based on evidence
• “Do no harm”—an individual responsibility
Safety is a system property
• Secrecy is necessary
Transparency is necessary
• Cost reduction is sought
Waste is continuously decreased
• Preference is given to professional roles over the system
Cooperation among clinicians is a priority

33. What we teach ( Content)
How we teach ( Structure)
When we teach ( Duration)
NEED CHANGE

34. Options for changing clinicians' practice behavior
1-Education
Passive: Providing information by CME, journals, books,
electronic media
Active: Provide answers to questions as they arise ("just-
in-time learning")
2-Change the work environment
Make it easier to do the right thing

35. • Options for changing clinicians' practice behavior
• 3-Feedback on performance
• Practice pattern reports for physician's use only
• Public report cards
• 4-Clinical practice guidelines
• Recommendations, tailored to local situation
• Should include an evidence-based rationale

36. • Options for changing clinicians' practice behavior
• 5-Local opinion leaders
Disease-specific network of respected colleagues
• 6-Persuasion
• 7-Economic incentives/disincentives
• Capitation, risk contracts
• Tying compensation to performance
• 8-Change patients' expectations

37. EBM process
1. Ask
2. Search
3. Appraise
4. Apply
5. Evaluate
Evidence-Based Medicine: How to Practice and Teach EBM by David Sackett

39. Ask
We need it twice for every 3 outpatient and 2
times for every inpatient cases
Questions are most likely to be about treatment
Most of the questions generated in consultations
go unanswered.

40. Clinical questions in daily practice
1-Is the finding abnormal?
2-What is the diagnosis?
3-How often does it occur?
4-What are the risk factors for the disease?
5-What is the pathogenesis?
6-What is the natural history?
7-How effective (and harmful) is treatment?
8-How effective (and harmful) are preventive
interventions?

41. EBM Process
When caring for patients creates the need for
information:
Translation to an answerable question

42. The search for the best answers to clinical questions begins
with a tight, explicit formulation of the question .
For example, the question "what is the best treatment for
type 2 diabetes?" is too general and broad to be answered
well.
For evaluating the effectiveness of an intervention, four
questions should be considered (commonly referred to as
"PICO")

43. PICO
●What is the relevant patient population?
●What intervention is being considered?
●What is the comparison intervention or patient
population?
●What outcomes are of interest?

44. An answerable relevant question may be:
"Among obese adults with type 2 diabetes, is
metformin more effective than sulfonylurea drugs
in preventing death?"

45. Answerable question
P: Among patients with NIDDM who are having MI
I: does tight control of their blood sugar
C: in comparison to conventional methods
O: reduce their risk of dying?"
EBM process

46. Example
• We want to know the effectiveness of
continuing medical education (CME)
programs for health care providers.

47. Formulate the question
• Health care providers (population)
• Continuing medical education (CME) seminars
and meetings (intervention)
• Skills, knowledge, attitudes / patient outcomes
(outcome)

48. Question components : PICO
• What types of Participants?
• What types of Interventions?
• What types of Comparison?
• What types of Outcomes?

49. What types of participants?
• Disease or condition of interest
• Potential co-morbidity
• Setting
• Demographic factors

50. What Types of Intervention?
• Treatment
• Diagnostic test
• Causative agent
• Prognostic factor
• Exposure to disease
• Risk behavior

51. What types of outcomes?
• Accuracy of diagnose
• Mortality/Survival
• Risk of disease
• Disease free period
• Quality of life
• Work absenteeism
• Disability/ Duration and severity of illness
• Pain

52. Outcomes
It is important to consider all patient-important outcomes
(including benefits and harms).
One must be specific about the outcomes of interest.
Outcomes should be well-defined, measurable, reliable,
sensitive to change, and should actually assess clinically
relevant aspects of a patient's health.

53. Types of outcomes measured in clinical studies include:
Composite endpoints :
The use of a composite of multiple combined endpoints
has the advantage of increasing the study's statistical
power but can be difficult to interpret.
Interpretation is easy if the intervention affects all
component outcomes to the same extent.

54. Types of outcomes measured in clinical studies include:
Composite endpoints :
• For example, in many cardiovascular treatment studies,
the outcome of death is combined with other adverse
outcomes (e.g., myocardial infarction, need for a
revascularization procedure).
• Since these outcomes may be valued differently, the use
of a composite outcome is confusing

55. • In a study comparing coronary bypass surgery with
percutaneous angioplasty and stenting for severe
coronary artery disease
the main study outcome was a composite of death, stroke,
myocardial infarction, or need for repeat revascularization
• Compared with bypass surgery, percutaneous
intervention had a significantly lower risk of stroke but
a significantly higher risk of repeat revascularization.
• The use of a combined endpoint under these
circumstances would be nonsensical.

56. Types of outcomes measured in clinical studies
Soft Outcomes
Much of clinical research focuses on objective outcomes,
which include the "hard" outcomes of death and disease
(for example, myocardial infarction, stroke, and loss of
limb).
The "softer" outcomes that measure function, pain, and
quality of life are less common

57. • Soft Outcomes
• Outcomes that require subjective interpretation by
patients or clinicians demand a carefully developed and
validated measurement tool.
• Subjective outcomes are usually more susceptible to the
placebo effect or expectation bias

58. • Types of outcomes measured in clinical studies
• Surrogate Outcomes
• Sometimes the most clinically important outcomes are
difficult to measure and a surrogate outcome becomes an
easier and cheaper substitute.
• 45 percent of the new medications approved by the US
Food and Drug Administration [FDA] between 2005 and
2012 were based on studies with surrogate outcomes

59. • A sobering example is the use of hemoglobin A1c as a
surrogate, or substitute, for the outcomes of diabetes
treatment that are clinically important (death, disease,
and dysfunction).
• Several therapies that demonstrated impressive
reductions in hemoglobin A1c were later found to have
no effect, or harm, on clinically relevant outcomes.

60. Background question
• Asks for general knowledge about a disorder
• Two essential components:
 A question root (who, what, where, when,
how)
 A disorder, or an aspect of a disorder
Type of Question

61. Type of Question
Foreground question
1.The patient and/or problem
2.The main Intervention
3.Comparison intervention
4.The clinical outcome .

64. EBM process
1. Ask
2. Search
3. Appraise
4. Apply
5. Evaluate

65. • Qualities of useful information sources for clinicians
include:
●Rapid access so the information can guide clinical
decisions as they arise
●Targeted to the specific clinical question
●Evidence-based, current research information
●Easy to use

66. • Answering all important clinical questions by reading,
appraising, and summarizing evidence would be
overwhelming and simply impossible for the individual
clinician.
• Therefore, the bulk of these tasks must be delegated to
trustworthy sources. UpToDate is a resource for this
purpose

67. EBM Process-Search
Two Efficient sources of the best evidence
Secondary (pre-appraised) sources
 Cochrane (systematic reviews)
 E-B Journals
Primary literature

68. Information Mastery
Usefulness of
medical
information
=
Relevance × Validity
Work

69. • Within the domain of information technology, a
distinction is made between a Database
which is a collection of bibliographic references to
medical articles :
Medical Literature Analysis and Retrieval System Online
[MEDLINE], Cumulative Index to Nursing and Allied
Health Literature [CINAHL], Excerpta Medica database
[EMBASE], Cochrane databases
• and an Access Portal, which is a user interface with a
built-in search engine (eg, PubMed, Ovid).

70. • EBM Process-Search
• Search filters
also called "hedges," "limits," "strategies," and
"clinical queries"
• are predefined search terms designed for a
specific purpose (eg, limiting searches to
guidelines, or randomized controlled trials).

71. • EBM Process-Search
• The Hierarchy of Evidence
1-Summaries and Guidelines
2-Systematic reviews and meta-analyses
3-Randomized controlled trials
4-Cohort studies
5-Case-control studies
6-Cross sectional surveys
7-Case reports.
8-Expert opinion (CME, Lectures, Rounds)

74. • Summaries and Guidelines
• Summaries and guidelines represent the highest level
of complexity.
• Ideally, guidelines are a synthesis of systematic
reviews, original research, clinical expertise, and
patient preferences.

75. Standards for guideline development have been put forth
by several organizations including:
the Grading of Recommendations Assessment,
Development, and Evaluation (GRADE) Working Group
the Institute of Medicine
and the Appraisal of Guidelines, Research, and
Evaluation (AGREE) Collaboration

76. • These standards are endorsed by numerous
organizations, including
• the United States National Heart, Lung, and Blood
Institute (NHLBI)
• the British National Institute for Health and Care
Excellence (NICE)
• the American College of Physicians
• the Cochrane Collaboration
• UpToDate

77. Question type Study type
Diagnosis Prospective validation study with blind,
independent comparison against a gold standard of diagnosis
Etiology or harm Case–control or cohort study
Prognosis Cohort study
Treatment or prevention Randomized controlled
Cost-effectiveness Economic evaluation
Quality of Life Qualitative research

78. How to hit the target?
All biomedical papers
Clinical studies
Relevant clinical studies
Relevant and valid clinical studies
Relevant, valid, new clinical studies

80. Original published
articles in journals
Cochrane reviews
Uptodate
Sources of clinically relevant and valid clinical studies:
Haynes’ 4S model
Computerised decision
support systems (CDSS)
Systems
Synopses
Syntheses
Studies

81. EBM process-Search
Two Efficient track-down of the best evidence
Secondary (pre-appraised) sources
 Cochrane (systematic reviews)
 E-B Journals
primary literature
Secondary Sources
Pre-digested information that is evidence-based
–Systematic reviews
–Practice guidelines

82. Systematic review
Comprehensively
• Locates
• Evaluates
• Synthesizes
all the available literature on a given topic
using a strict scientific design which
must itself be reported in the review

83. A ‘systematic review’ aims to be:
• Systematic ( in its identification of literature)
• Explicit ( in its statement of objectives, materials and
methods)
• Reproducible ( in its methodology and conclusions)

84. Systematic Reviews
• Clear statement of purpose and scope
• Comprehensive search and retrieval of the relevant
research
• Explicit selection criteria
• Critical appraisal of the primary studies
• Reproducible decisions regarding relevance, selection,
and methodologic rigor of the primary research
• When quantitative methodology applied -> meta-
analysis

85. Systematic Reviews & Meta-Analyses
[Syntheses]
• Cochrane Database of Systematic Reviews
• Database of Abstracts of Reviews of Effects (DARE)

86. “It is surely a great criticism of our profession that we have not organised a
critical summary, by specialty or subspecialty, adapted periodically, of all
relevant randomised controlled trials.”
Archie Cochrane

87. Cochrane Library
1. Cochrane Database of Systematic Reviews
(CDSR)
2. Database of Reviews of Effectiveness
(DARE)
3. Cochrane Controlled Trials Registry (CCTR)

88. EBM process
1. Ask
2. Search
3. Appraise
4. Apply
5. Evaluate

89. EBM process
3 -Critical Appraisal of the evidence for its
validity and clinical applicability

90. ASSESSING THE VALIDITY OF THE EVIDENCE
Clinicians should have the skills necessary to
critically evaluate research articles that are
important to their practice.
Critical appraisal skills enhance mastery and
autonomy in the practice of medicine.

91. • ASSESSING THE VALIDITY OF THE EVIDENCE
• A number of guidelines are available that describe
standards for conducting and reporting different types
of studies.
• The set of guidelines endorsed by the International
Committee of Medical Journal Editors can facilitate the
critical appraisal of individual studies based on the type
of study:

92. • Standards for Conducting and Reporting
●Systematic reviews and meta-analyses – Preferred
Reporting Items for Systematic Review and Meta-Analysis
(PRISMA)
●Randomized controlled trials – Consolidated Standards
of Reporting Trials (CONSORT) and Standard Protocol
Items: Recommendations for Interventional Trials
(SPIRIT)

93. • Standards for Conducting and Reporting
• Observational studies – Strengthening the Reporting of
Observational Studies in Epidemiology (STROBE)
●Diagnostic and prognostic studies – Standards for
Reporting of Diagnostic Accuracy (STARD) and
Transparent Reporting of a multivariable prediction model
for Individual Prognosis Or Diagnosis (TRIPOD)

94. CRITICAL APPRAISAL
There are three possible explanations for the results of any
study:
• The study was biased toward producing that result.
The result happened by chance.
The result happened because it represents the truth.
 Critical appraisal is about ruling out the first two
possibilities

95. DECIDING ON VALIDITY
There are three things you need to ask yourself about any
piece of evidence you find:
Does it address a clearly focused, relevant question?
Is it valid?
Are the valid results important?
If the answer to any one of these questions is “No,” you
can save yourself the trouble of going any further

96. The focus of critical appraisal is judging both internal
validity and generalizability (external validity)
Internal validity — Internal validity refers to the
question of whether the results of clinical research are
correct for the patients studied.
Threats to internal validity include bias and chance

98. • DECIDING ON VALIDITY
• ●Bias – Bias is any systematic error that can produce a
misleading impression of the true effect. Randomized
trials are performed with the aim of reducing bias
• Chance – Chance is random error, inherent in all
observations. The probability of chance producing
erroneous results can be minimized by studying a large
number of patients

99. Potential sources of bias in randomized trials include:
•Failure to conceal random assignment to those enrolling
study subjects
•Failure to blind relevant individuals (including study
participants, clinicians, data collectors, outcome
adjudicators, and data analysts) to group assignment
•Loss to follow-up (missing outcome data)
•Failure of adhere to assigned intervention
•Stopping early for benefit
•Preferentially publishing small (underpowered) studies
with statistically significant results (publication bias)

100. External validity — External validity refers to the question
of whether the results of the study apply to patients outside
of the study
Study patients are typically highly selected, unlike patients
in usual practice.
They have been referred to academic medical centers, meet
stringent inclusion criteria, are free of potentially
confounding conditions or disorders, and are willing to
countenance the rigorous demands of study protocols

101. Critical appraisal of guidelines or articles for their quality and
the usefulness of their results
Appraise the guideline or article you chose for its internal
validity
Appraise the guidelines for its external validity
Check its results.

102. 1. Appraising the internal validity (quality) of the RCTs
This is the most complex part of critical appraisal. The essential questions
to ask are:
Is the assignment of patients randomised?
Is the randomisation concealed?
Are patients, health workers, and study personnel blind to treatment?
Aside from the experimental intervention, are the groups treated equally?
Are patients analysed in the groups to which they were randomised?
Is follow up complete?

103. Is the assignment of patients randomised?
The key feature of a randomised controlled trial is its method to achieve
allocation to groups. the methods section
Is the randomisation concealed?
Concealment can be defined as blinding at the point of randomisation. For
example, if the trial organisers pack envelopes with codes themselves,
this may not be concealed because it is possible for the researchers to
manipulate the contents of envelopes thereby introducing selection bias.
For the trial to be concealed the randomisation process should be carried
out by a third party. This third party would perform the randomisation
and only they would have knowledge of the allocation sequence

104. Are patients, health workers, and study personnel blind to
treatment?
You should not confuse blinding with concealment.
Blinding is a method in which trials can attempt to eliminate bias by
keeping participants and clinicians unaware of the treatment
allocation after randomisation has been carried out.
Blinding is useful in helping to prevent performance and
measurement bias

105. There are different levels of blinding:
Single blind - this is when the patient does not know which treatment
they have been allocated to
Double blind - this is when the clinicians and patients do not know
which treatment patients have been allocated to
Triple blind - this is when the clinicians, patients, and outcome
assessors do not know which treatment patients have been
allocated to.

106. Aside from the experimental intervention, are the groups
treated equally?
Groups must be treated equally in every way except for the
intervention. Blinding clinicians and patients helps to
achieve this.
To treat groups equally researchers need to strictly adhere
to a pre-specified care protocol

107. Are patients analysed in the groups to which they were
randomised?
This question asks whether the trial has used intention to treat or
another form of analysis
Intention to treat analysis is the best way to analyse data for
effectiveness.
It means that even if for any reason participants move from one
treatment arm of the trial to another, they should still be analysed
in the group to which they were originally allocated and not in
their new group.

109. Checking the external validity
Now you have found that your study is internally valid
because it fulfils the six points described above. But is it
also externally valid?
External validity refers to whether the internally valid
results can be applied to patients outside the study

110. What are the results?
When reading papers about therapies there are a number of ways in
which the effects of treatment can be measured.
You need to understand the differences between the following four
measurements:
Relative risk or risk ratio
Odds ratio
Absolute risk reduction
Number needed to treat.

111. Risk
The risk of an event happening is the chance of that event
happening divided by the number of possible chances.
So the risk of throwing a six with a normal die is one in six

112. odds
The odds of an event are the chances of the event
happening divided by the chance of the event not
happening.
So the odds of throwing a six with a normal die are one in
five.
(The chance of the event happening is 1/6 and the chance
of the event not happening is 5/6. Dividing these = 1/5)

115. Numbers needed to treat
Odds ratios and relative risk are not always well understood by
clinicians
The number needed to treat is a more clinically meaningful
measurement of consequences of treatment.
The number needed to treat is the number of patients that we
have to treat to cause one additional positive outcome.
Numbers needed to harm looks at negative outcomes.

116. Experimental group event rate = a/(a+b)
Control group event rate = c/(c+d)
Absolute risk reduction = control group event rate -
experimental group event rate

117. The reciprocal of the absolute risk reduction is the number
needed to treat:
Number needed to treat = 1/absolute risk reduction =
1/(control group event rate - experimental group event
rate)

118. Statistical power
You may want to find out whether a study has enough
participants to be sure that its results are not based on
chance.
In randomised controlled trials the researchers would have
calculated the number of people they will need in their
study to observe the change they predict with
confidence (power in statistical terms).

119. 
Confidence intervals
Two questions you can ask yourself about the confidence intervals:
Do they cross the “line of no difference”? If they do, then the results
are not statistically significant. Maybe their sample was too
small.
Would your clinical decision be the same if the true value was at the
top of the CI range as if it were at the bottom? Is the CI so wide
that you cannot rely on the result?
Clinical papers should report confidence intervals around their
results. If they do not, be suspicious

120. DECIDING ON RELEVANCE
You can make the problem more manageable by breaking it down
according to the following three-part question:
Are your patients similar to those in the study?
Can your service provide the intervention in the same way as in the
trial?
Do the outcomes from the study match up with the ones that matter
to you and your patients?

121. EBM process
1. Ask
2. Search
3. Appraise
4. Apply
5. Evaluate

122. EBM process
Apply: Integration of critical appraisal with
clinical expertise and the patient’s unique
biology and beliefs
Evaluation of one’s performance.

123. What Proportion of Healthcare is Evidence-
Based ?
• BMJ Editorial: about 15%
• Archie Cochrane: less than 10%
• NIH : 20 %

124. • Seven alternatives to Evidence Based Medicine
1-Eminence-based medicine
2-Vehemence-based medicine
3-Eloquence-based medicine
4-Providence-based medicine
5-Diffidence-based medicine
6-Nervousness-based medicine
7-Confidence-based medicine
BMJ 1999

125. Class0:Things I believe
Class0a:Things I believe despite the available data
Class1:Randomised controlled clinical trials that agree with what I believe
Class2:Other prospectively collected data
Class3:Expert opinion
Class4:Randomised controlled clinical trials that do not agree with what
I believe
Class5:What you believe that I do not
Evidence Based joke
Egocentrism

126. • Imagine your life and the lives of your friends and
family placed in the hands of juries and judges who
• let their biases and stereotypes govern their
decisions,
• who do not attend to the evidence,
• who are not interested in reasoned inquiry,
• who do not know how to draw an inference or
evaluate one.