Presentation on basics of EBM in Riga, Latvia.

1. Evidence based medicine
Professor Janko Kersnik, MD, MSc, PhD
Family doctor in a branch office Kranjska Gora, Slovenia
Head of Family Medicine Department, Medical School Maribor
Head of Research Department, Department of
Family Medicine, Medical School Ljubljana
President of Slovenian Family Medicine Society
President of EURACT

2. Structure of the presentation
1. Principles of EBM
2. Demonstration in searching evidence
3. Assessment of the evidence (paper)
4. Information for group work: Exercise in
assessment of evidence
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3. Variation to the theme
s Evidence based medicine
s Scientific medicine
s Evidence based practice
s ...
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4. Read thread of EBM
s Patient dilemma
s Ask clinical question
s Acquire (search) evidence
s Apprise (assess) evidence
s Apply in everyday practice
s Act (monitor change)
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5. Aim of the first part
s To demonstrate how by using IT we can
get answers to clinical questions.
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6. Literature
s http://
www.hsl.unc.edu/services/tutorials/ebm/w
s http://medlib.bu.edu/tutorials/ebm/
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7. By the end of the first part you will
s Know how to set clinical question
s Know key electronic databases
(Medline, Cochrane, Clinical Evidence)
s Know how to get them (Internet, CD,
book)
s Understand and value evidence for safe
work
s Be able to use evidence for your
everyday practice
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8. What do we know on EBM?
s Buzz groups – discuss in groups of
three
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9. What is EBM?
s Evidence instead experience and
eminence
s Use of IT in everyday practice
s An answer to patient demands
s “New religion” which is changing our
practice
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10. What is EBM practice?
s EBM is defined as an application of best
research evidence in everyday patient
care.
s EBM is defined as clinical decision
which is based on systematic search,
assessment and application of
evidence.
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11. EBM-4
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12. Four steps in searching
evidence
1 2
3 4
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13. 1 Clinical question
s To begin the EBM search process start
with a well-developed and answerable
question. A good clinical question will:
– Save time when researching
– Keep the focus directly on the patient's
need
– Suggest the appropriate form that a useful
answer may take
s The clinical question will impact the
entire EBM literature searching process.
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14. Typical questions
s Therapy
s Diagnostics
s Prognosis
s Prevention
s Health promotion
….
s What should I do for this patient?
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15. PICO
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16. Questions
s Who is your patient?
s What is the intervention?
s What is the comparison?
s What is the outcome?
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17. Your patient
s In your 83-year old patient, who is 25
years treated for high blood pressure, which is
well organized with the average blood pressure
values below 140/90 mmHg, you have found at
a regular check up an irregular heart
rhythm, which is on the ECG proved atrial
fibrillation. Does not have any other diseases, he
is in good physical and mental condition. Since
you do not have data on the beginning of
this disorder, you have referred him to a
cardiologist. He returns with
the result, from which you read, that he has
undergone unsuccessful cardio conversion. The
patient prefers aspirin, which does not require
any monitoring, over proposed warfarin.
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18. Patient dilemma
s Shall we follow the guidelines or is
there evidence that we can take into
account patient preferences?
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19. In small groups...
...define clinical
question from
your practice,
…or define clinical
question from the
case of our 83-
years old patient.
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20. Clinical question in our case
s Is treatment with aspirin (I) in the 83-
year old patient with chronic atrial
fibrillation (P) as effective as warfarin
(C) in terms of prevention of
stroke and total mortality and
complications of treatment (O)?
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21. Searching evidence
s Where do you search information?
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22. Hierarchy of evidence
s Systematic reviews
s Meta-analyses
s RCT
s Prospective studies
s Retrospective studies
s Case reports
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23. Types of studies
(iz: Silagy and Haines, Evidence Based Practice in Primary Care,
BMJ Books, 1998)
O b s e rv a tio n a l E x p e r im e n ta l
D e s c r ip tiv e A n a ly t i c a l U n c o n t r o lle d C o n tr o lle d
C o h o rt C a s e -c o n tro l N o n - r a n d o m is e d R a n d o m is e d
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24. Sources
s Medline
s Cochrane
s Clinical Evidence
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25. MEDLINE
s From 1966
s Internet based
s Search; PubMed - http://
www.ncbi.nlm.nih.gov/pubmed/ (http://
www.ncbi.nlm.nih.gov/sites/entrez )
s Usual terms
s Option “find related data; PubMed; related
articles”
s Option “Also try”
s Options to copy in a file (Send to; File) or in own
data base (Reference manager)
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26. Strategy
s Search; MeSH (Medical Subject
Headings)
s English terms
s Operators (and, not, or)
s Limits (author, title, abstract, language)
s “Find related articles”
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27. http://www.ncbi.nlm.nih.gov/sites/entrez
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29. COCHRANE
s Systematic reviews, RCT
s Internet
s Rigorous inclusion criteria
s Regular update
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32. CLINICAL EVIDENCE
s Book twice a year
s Relevant clinical questions
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34. Find in Internet relevant papers for
the subject you are interested!
Select one you want to apprise.
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35. Search for our patient
s MeSH: warfarin aspirin stroke prevention not
dabigatran
s Limits
– RCT or systematic reviews,
– Not older than 5 years,
– Human,
– Male, older than 80 years,
– English,
– Free papers.
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36. Search results for our patient
s We got 7 hits.
s After reading titles and abstracts we were left with
two of them:
– Williams JE, Chimowitz MI, Cotsonis GA, Lynn MJ, Waddy
SP; WASID Investigators.Gender differences in outcomes
among patients with symptomatic intracranial arterial
stenosis. Stroke. 2007 Jul;38(7):2055-62. Epub 2007 May
31.
– Rash A, Downes T, Portner R, Yeo WW, Morgan N,
Channer KS. A randomised controlled trial of warfarin
versus aspirin for stroke prevention in octogenarians with
atrial fibrillation (WASPO). Age Ageing. 2007
Mar;36(2):151-6. Epub 2006 Dec 15.
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37. Conclusions for the first part
s Searching can make fun
s There are simple tools available
s Practice make expert
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38. Appraisal (assessment/evaluation of
evidence)

39. Aims of the second part
s What is medical literature?
s What types of documents/papers do we
know?
s Sources of primary documents
s Criteria for papers, guidelines, meta-
analyses. Systematic reviews
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40. Medical literature
s Primary documents
– primary (research) paper
– diploma, masters,
doctoral thesis
s Secondary documents
– review paper
– meta-analysis
– seminar work
– guidelines
s Tertiary documents
– textbook
– handbook
– congress proceedings
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41. Sources of primary documents
s Specialist theses
s Graduate theses
s Maister theses
s Doctoral tehses
s Medical journals
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42. Strengths and weaknesses of
primary documents
Strengths Weaknesses
s Original, s Large number of
unpublished work papers
s Source of new s Evidence is mainly
knowledge scattered over
s Basis of scientific several journals
development
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43. Structure of primary document
s Title s Results
s Abstract – Sample description
– Key results
s Introduction – Additional analyses
– “What was the
problem?” “Why is this s Discussion
problem interesting for – On methods
a reader?” – On results
s Aims, hypothesis s Conclusions
s Methods and patients s Acknowledgement
– Methods s Financial disclosure
– Patients - sampling
– Study description
s “Conflict of interest”
– Data analysis s References
s Appendices
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44. External grading of “reliability”
of the source – medical journal
s External reviewers
s Indexed
s On Medline
s SCI: science citation
index, SSCI: social
science citation
index
s IF: impact factor
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45. Appraisal of “usefulness” of the paper
s Check in aims and Hypotheses,
– If they agree with your need for information;
s In methods check,
– If the paper studies same population as yours;
– If the study subject complies with your need
– If sample size and study power are given;
– If appropriate statistical methods were used;
s In results check,
– For ev. biases and flaws;
– If the results are valid for your practice;
– If the statistical significance has also any clinical
meaning. EBM 45
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46. IMRAD
s Introduction (why the authors decided
to do this research),
s Methods (how they did it, and how
they analysed their results),
s Results (what they found), and
s Discussion (what the results mean).
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47. Paper quality criteria
– introduction and methods
s Is the purpose clear?
s What is the measure of the study succes?
s Is the methodology understandable?
s Where are the patients from?
s What is the selection of patients?
s Methods of data collection
s What is the percentage of responses?
s Is the number of observations sufficient?
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48. Paper quality criteria
– results and conclusions
s Whether they used appropriate
statistical methods?
s Are the results shown appropriately or
misleading?
s Are there confidence intervals shown?
s Are the conclusions based on the study
results?
s Are the authors aware
of limitations and potential biases?
s Recommendations for further study?
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49. Methods
s Random allocation of study participants
s Researchers were blinded for the initial
allocation
s The groups did not differ at the beginning of
the study
s Researchers were blinded for actual
allocation
s Was analysis performed on all included
participants?
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50. Appraisal of recomendations in
the guidelines
(GRADE, BMJ 2004, 328: 1490-8)
s A: The opinion supports
more quality studies - there is no
major change in knowledge expected.
s B: Opinion supported by
one or more major study weaker or incomplete
study - we can expect changes in knowledge.
s C: Opinion support some studies, but not
always quality ones - future research is likely
to result in significant changes in knowledge.
s D: No reliable conclusion is possible.
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51. Appraisal of meta-analysis
(Cochrane)
s Described protocol of meta-analysis
s Description systematic literature search
s Criteria for inclusion or exclusion
of studies, research, and that all the
reasons why they were excluded
s The homogeneity of the results shown by tests
s Appropriate statistical analysis were used
s In the case of statistically significant
differences the possibility of biases due to
variability of studies explained
s Conclusions shown with regard to
treatment decisions EBM
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52. Conclusions
s Knowledge becomes quickly
obsolete, or new replaces old dogmas.
s Physicians must follow new findings.
s Information is unlimited, our ability is
limited.
s Reliance on the eminence does not suit
any more.
s We urgently need to know how to find
and use appropriate sources of new
knowledge.
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53. Thank you very much for your
attention!

54. Group work: Evaluate papers!
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