1. 1
Introduction to
Evidence-Based Medicine(EBM)
A new approach to clinical care and research
Binyam Tariku
School of Public Health
Dilla University
A new approach to clinical care and research

2. 2
But first, a test…

3. A. Training, clinical experience and consultation with
other professionals
B. Convincing evidence (non-experimental) from
articles, case reports, product literature, etc.
C. Preferences of the patient
D. Active search of Randomized Controlled Trials,
Systematic Reviews, Meta-Analysis Reports
WHAT IS THE BASIS OF YOUR MEDICAL PRACTICE?
(Check all that apply)
3

4. A. Training, clinical experience and consultation with
other professionals
B. Convincing evidence (non-experimental) from
articles, case reports, product literature, etc.
C. Preferences of the patient
D. Active search of Randomized Controlled Trials,
Systematic Reviews, Meta-Analysis Reports
WHAT IS THE BASIS OF YOUR MEDICAL PRACTICE?
EXCELLLENT!
4

5. BUT… Past knowledge and practice might be outdated or inadequate
Graduate Medical School Practiced Physician
5

6. A. Training, clinical experience and consultation with other
professionals
B. Convincing evidence (non-experimental) from articles, case
reports, product literature, etc.
C. Preferences of the patient
D. Active search of Randomized Controlled Trials, Systematic
Reviews, Meta-Analysis reports
WHAT IS THE BASIS OF YOUR MEDICAL PRACTICE?
FANTASTIC!
6

7. BUT… This evidence may be biased, outdated, incorrect, or not applicable to your patient
ARTICLES
ADVERTISEMENTS
JOURNALS (1987 to present)
7

8. about 1/2 of ‘valid’ evidence today is out
of date in 5 years
ScienceCartoonsPlus.com
 about 1/2 of valid evidence is not
implemented
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9. A. Training, clinical experience and consultation with other
professionals
B. Convincing evidence (non-experimental) from articles, case
reports, product literature, etc.
C. Preferences of the patient
D. Active search of Randomized Controlled Trials, Systematic
Reviews, Meta-Analysis reports
WHAT IS THE BASIS OF YOUR MEDICAL PRACTICE?
WONDERFUL!
Mutual Respect +
Shared Goals =
Better Cooperation and
Compliance
9

10. The patient should be involved in all important decisions
But this is NOT always an easy task!
And conflicts WILL occur!
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11. Education about current alternatives and risks is often needed… for both the Patient
and the healthcare provider!
Patient C
But doctor, I DO want to
have children!
Patient A
No salt?
Lose weight?
Forget it!
Just give me a pill!
Patient B
I WON’T take that medicine… The
side effects are INTOLERABLE!
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12. I’ll discuss those risks with
my husband.
Yes, I’d like to try that new
medication!
Wow…
I never knew that high
blood pressure could be so
dangerous at my age!
Education about current alternatives and risks is often needed… for both the
Patient and the healthcare provider!
12

13. A. Training, clinical experience and consultation with other professionals
B. Convincing evidence (non-experimental) from articles, case reports, product literature, etc.
C. Preferences of the patient
D. Active search of Randomized Controlled Trials, Systematic Reviews, Meta-Analysis reports
You are practicing EVIDENCE BASED MEDICINE!
CONGRATULATIONS!
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14. 14

15. 0
500000
1000000
1500000
2000000
2500000
Biomedical MEDLINE Trials Diagnostic?
Medical
Articles
per
Year
5,000?
per day
2,000
per day
75 per
day
Articles
Per
Year
why do we need to use evidence efficiently?
EBP: informing decisions with the best up-to-date evidence
15

16. The chart below shows the distribution of locations for all studies registered on ClinicalTrials.gov.
Percentage of Registered Studies by Location (as of April 20, 2023)
Total of 449,470 studies
EBP: informing decisions with the best up-to-date evidence
16

17. 0
500000
1000000
1500000
2000000
2500000
Biomedical MEDLINE Trials Diagnostic?
Medical
Articles
per
Year
Articles
Per
Year
Number of Registered Studies Over Time
The graph and table below show the total number of studies posted on ClinicalTrials.gov since 2000, based on
the First Posted date. The first version of ClinicalTrials.gov was made available to the public on February 29,
2000.
EBP: informing decisions with the best up-to-date evidence
17

18. Bastian, Glasziou, Chalmers PLoS 2010 Vol 7 | Issue 9 | e1000326
more efficiently
Clinical evidence increasing so rapidly we need better skills to keep up-to-date more efficiently
than previous generations of clinicians
18

19. Bastian, Glasziou, Chalmers PLoS 2010 Vol 7 | Issue 9 | e1000326
more efficiently
Clinical evidence increasing so rapidly we need better skills to keep up-to-date more
efficiently than previous generations of clinicians
19

20. EVIDENCE BASED MEDICINE
A new approach to clinical care and research
1. Definition of EBM
2. Level and type of Evidence
3. Basic Steps
4. Trials, Studies and Reports
5. Pros, Cons and Limitations
6. EBM in Developing Countries
7. EBM Library
8. Advanced EBM
“A 21st century clinician who
cannot critically read a study is
as unprepared as one who
cannot take a blood pressure
or examine the cardiovascular
system.”
BMJ 2008:337:704-705
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21. 21
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. David Sackett defines EBM as:
“…The conscientious, explicit, and judicious use of current best evidence in making decisions about
the care of individual patients.”
“And where did it come from?”
“What is Evidence Based Medicine?”
HISTORY BACKGROUND OF EBM

22. 22
Evidence Based Medicine
It is a change in the way physicians/healthcare providers 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 rigorous approach, better proof criteria (more demanding of proof, less room for error)

23. 23 Summary: Evidence Based Medicine
“the conscientious use, explicit, and judicious use of current best
evidence in making decisions about the care of individual patients.
Sackett DL, et al. Evidence-based medicine: what it is and it isn’t. BMJ 1996;312:71-2.
Integration of best research evidence with clinical expertise and patient
values.

24. 24
Evidence Based Medicine
Patient
Values
Clinical
Expertise
Research
Evidence
Medical Decision
THREE MAJOR COMPONENTS of EBM

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LEVEL AND TYPE OF EVIDENCE

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Level of Evidence

27. 27
Level of Evidence

28. 28
Level of Evidence

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Types of Resources

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Types of Resources

31. 31
Types of Resources

32. 32 What skills will you need
to keep up to date with the
best evidence?
Must be aware of their responsibility to
maintain their knowledge and skills throughout
there careers.
Students are expected to keep up to date and to
apply knowledge necessary for good clinical
care.
▹ to find the evidence more efficiently
▹ to appraise the quality of the evidence more effectively
▹ to use good quality evidence more systematically

33. Basic Steps Of EBM
33

34. Basic Steps Of EBM
1. Ask a relevant, focused question
2. Acquire the necessary resources to
answer the question
3. Appraise the evidence obtained
4. Apply to patient care
5. Evaluate the intervention/EBM process
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35. The Clinical Question/Problem
35
The FIRST step
The HARDEST step
The MOST IMPORTANT step!
A GOOD QUESTION…
• Is focused and relevant
• Provides clear communication
• Clarifies your goal or need
• Will reduce the amount of time
needed to obtain the answer
1. ASK( Clinical question or problem)

36. 36 FACT: We all have informational needs!
That is not a problem!
36

37. Problems arise
• if we fail to recognize those needs
• if we fail to bridge the information gap
• if we fail to ask the right questions
37

38. 38
• Be specific
Identify the problem, clarify the
clinical issue
• Be answerable
through the literature
• Contain multiple aspects
(patient, options, comparisons,
etc)
WHEN PRACTICING EBM:
It should NOT involve a question of
Personal Preference or Local Concern.
Patient presenting with MI

39. BACKGROUND and FOREGROUND QUESTIONS (all part of EBM)
FOREGROUND QUESTIONS
BACKGROUND QUESTIONS
NEW POSSIBILITIES
INDEFINITE ANSWERS
“Where do we want to go,
and how else might
we get there?”
“Where are we now?
And which way are we headed?”
BASIC & CONCRETE
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40. ▸ About the disorder, test, treatment, etc.
▹ a. Root* + Verb: “What causes …”
▹ b. Condition: “HIV?”
• * Who, What, Where, When, Why,
Know your background
40
BACKGROUND QUESTIONS

41. BASIC & CONCRETE
1. QUESTION
• Who, What, Where, When, Why, How
2. VERB
• is, causes, does, treats, reduces, cures, prevents, affects
3. GENERAL KNOWLEDGE ABOUT DISORDER
clinical manifestations of disease, patient findings, differential
diagnosis, etiology, patient experience, comorbid condition, screening
and diagnostic tests, prognosis, therapy, risk factors, etc.
41
BACKGROUND QUESTIONS

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Patient presenting with MI
1. What are the symptoms and signs of someone presenting
with MI?
2. What are the diagnostic tests for MI?
3. What are the causes of MI?
4. What are the treatments of MI?

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Patient presenting with MI
Foreground Questions
About actual patient care decisions and actions
For treatment 4 (or 6) components:
In Patients with a MI
Does (I) cholesterol lowering therapy
Compared to placebo
reduce mortality (O)
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46. NEW POSSIBILITIES
INDEFINITE ANSWERS
PT AND/OR PROBLEM Differential dx, Unusual presentation, uncertain etiology, pt’s
prior experience, comorbid conditions
INTERVENTION Exposure, test. Prognostic factor,
treatment, pt perception, etc.
COMPARISON INTERVENTION
OUTCOMES
EXPERT
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FOREGROUND QUESTIONS

47. Patient presenting with MI
1. How common is the problem Prevalence
2. Is early detection worthwhile Screening
3. Is the diagnostic test accurate Diagnosis
4. What will happen if we do nothing Prognosis
5. Does this intervention help Treatment
6. What are the common harms of an
intervention
Treatment
7. What are the rare harms of an
intervention
Treatment
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48. ▹ www.getintopc.com
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49. EBM QUESTION: Should include multiple factors
(Examples)
P PATIENT type of patient or population
Ex: 47 yr male w/DM2 and cellulitis toe, 25 yr female w/DVT and chest pain
E EXPOSURE environmental, personal, biological
Ex: TB, tobacco, drug, diet, pregnancy or menopause, MRSA, allergy
I INTERVENTION clinical intervention
Ex: medication, procedure, test, surgery, radiation, drug, vaccine
C COMPARISON compare alternative treatment
Ex: other prior, new or existing therapy
O OUTCOME clinical outcome of interest
Ex: Reduced death rate in 5 yrs, decreased infections, fewer hospitalizations
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50. ELEMENT PROMPTS THE QUESTION:
Patient How would I describe a group of patients similar to mine?
Intervention What main action am I considering?
Comparison What is/are the other options?
Outcome What do I (or the patient) want to happen (or not happen)?
Example:
P: In kids under age 12 with poorly controlled asthma on metered dose inhaled steroids…
I: would the addition of salmetrol to the current therapy
C: compared to increasing the dose of current steroid
O: lead to better control of symptoms without increasing side effects?
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FRAMING THE QUESTION (Example: PICO)

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MAJOR CATEGORIES
1. Diagnosis
2. Prognosis
3. Therapy/ Treatment
4. Harm (iatrogenic, other)
MISCELLANEOUS
• Quality of care
• Health economics
• Office Management
• Etc.
CATEGORY OF QUESTION

52. 52 Must be considered!
Often QUALITATIVE (not based on measureable outcomes)
Feelings, ideas, experiences, preferences, concerns, fears, beliefs, ethnicity
Usually based on LIMITED BACKGROUND
Perception of problem
Self-diagnosis
Treatment wanted or needed
Alternatives (read, heard, considered, tried)
What is the patient hoping to avoid?
What benefits does the patient want or need most?
Etc.
THE PATIENT’S QUESTIONS

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QUANTITATIVE: “Solid Evidence”
• Measurable answer or response
• Necessary for scientific study
• Necessary for the practice of EBM
QUALITATIVE: “Quality of Life”
• “Fuzzy” data - Impact on daily life, work, family, etc.
• May be very important and influential to decisions – especially for the patient
• Creates added challenge or twist to practice of EBM
QUANTITATIVE vs QUALITATIVE QUESTIONS

54. “ Acquire(Search) Evidence”
HINT: If your desk looks like this, it’s probably the LAST place you should start
looking!
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Find the Best Evidence

55. Learn and Practice various SEARCH STRATEGIES:
• To find useful information quickly
• To eliminate irrelevant, inappropriate or weak information
Try to develop the habit of learning as you go;
Not just in lengthy formal sessions!
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SEARCH AND RETREIVE THE BEST EVIDENCE

56. Find the Best Evidence
“The Literary Search”
The BEST EVIDENCE is:
External - from outside resources (researchers, experts)
Current – not out of date, most recent
High Quality - accurate, precise, effective, safe
Patient focused - applicable and appropriate for your individual patient
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SEARCH AND RETREIVE THE BEST EVIDENCE

57. 1. IDENTIFY NEEDS: What type of information is needed?
2. IDENTIFY RESOURCES: Types, Availability, Timeliness,Costs?
3. SEARCH & RETRIEVE: Use efficient strategies
4. REVIEW : Check quality and usefulness of info
5. INTERPRET: Help patient understand info, application
57
FIVE STEPS TO FINDING THE BEST EVIDENCE

58. WHAT CATEGORY IS THE QUESTION?
• Diagnosis
• Prognosis
• Therapy
• Harm
58
WHAT TYPE OF INFORMATION IS NEEDED?

59. There are MANY study designs!
EXPERIMENTAL TRIALS
(Answers questions of diagnosis or treatment)
Randomized Controlled Trials (RCTs)
Controlled studies
Blinded vs Open
ETC.
OBSERVATIONAL STUDIES
Descriptive reports
Retrospective studies
Cohort studies
Case Control
ETC.
59
WHAT STUDY DESIGN FITS IT BEST?

60. Randomized Controlled Trials (RCT)
“Gold Standard” of research
Ideal experimental design - Best design for TREATMENT questions
Must identify objective of treatment
(Ex: cure, prevent complication, palliation, reassurance)
Still not always the right intervention for individual patient at that particular time and place
60
EXAMPLE

61. CLINICAL PRACTICE APPROPRIATE DESIGN FOR CLINICAL RESEARCH
Diagnosis, Dx testing Cross-sectional study – not randomized trial
Prognosis Follow-up studies of patients evaluated at same early point of illness
Therapy, treatment RCT or Systematic review of multiple RCTs must be used
Avoid non-experimental approaches to avoid false conclusions about efficacy
Exceptions:
When treatment may be successful in an otherwise fatal condition
When no studies are available (rare conditions, new treatments, etc.)
Harm RCT, Cohort, Case-control
OTHER INFORMATIONAL
Explore hypothesis Qualitative research
History-taking Case control study
Individual trial & error n of 1 trial
Following clinical courseCohort study
Recordkeeping Systematic registry-based (computer supported) research
Quality of Care research Individual peer review, Process Evaluation
MISCELLANEOUS Basic Science, Genetics, Immunology, etc. 61
What type of evidence best addresses the question, problem or issue?

62. Case report
Controlled Trial
Systematic review
Meta-analysis
Clinical guidelines
etc.
62
WHAT FORM OF INFORMATION?

63. IDENTIFY YOUR RESOURCES
Colleagues
Consultation, Discussion
(Caution: Response may be an outdated “This is what we do”)
Paper resources
books, reports, journals
Electronic databases
Health Literature Services
specialized librarians, staff
Review services, Abstract Services, etc.
63
LITERARY SEARCH: NEXT STEP

64. OVERVIEW
64

65. the steps of practicing EBM
1. Ask a focused question.
2. Track down the evidence
3. Critically appraise evidence for its validity, effect size, precision
4. Apply the evidence in practice:
a. amalgamate the valid evidence with other relevant information (values &
preferences, clinical/health issues, & system issues)
b. implement the decision in practice
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