Why bother with
Evidence-Based Practice?
Professor Paul Glasziou
Bond University
www.crebp.net.au/
www.testingtreatments.o...
Introductory Lecture: Objectives
What is Evidence-Based Medicine?
The steps of doing EBM
1. Formulate Clinical Questions
2...
What is Evidence-Based Medicine?
“Evidence-based medicine is the integration of best
research evidence with clinical exper...
“EBM” - birth of a term
Update of CMAJ series on how
to read a paper
JAMA User guides 1991
authors seek a new term
Clinica...
The need for Evidence
Vertebroplasty for osteoporotic fractures
Gray et al Spine 2008. Nation-wide and State-specific prim...
Unnecessary Procedures
http://www.cbsnews.com/8301-18563_162-5217954.html
Please click on the black screen to view the vid...
that did not work
 Vertebroplasty for osteoporotic fractures (NEJM,
2010)
 Arthoscopic knee lavage (Moseley, NEJM, 2002)...
Most medical innovations don’t work
an analysis of 136 trials in myeloma
New Treatment
Better
New Treatment
Worse
How can we find the research that will improve
the care of our patients?
0
500000
1000000
1500000
2000000
2500000
Biomedic...
What should you believe?
Keeping up to date
What is your JASPA* score?
* (Journal Associated Score of Personal Angst)
J: Are you ambivalent about r...
Coping with the overload:
three possible things you might try
A. Read an evidence-based
abstraction journal
(and cancel ot...
Part 2: The 4 steps of “pull” EBM
1. Formulate an answerable question
2. Track down the best evidence
3. Critically apprai...
Step 1
Formulate an answerable clinical question
Structure of researchable
questions – PICO-T
 Population/Patients
 Inte...
Formulating answerable clinical
questions
Structure of researchable
questions – PICO-T
 Population/Patients
 Outcome
What are your clinical questions?
 A 35 year old man says his brother
recently died of a ruptured
cerebral aneurysm.
He i...
Risk Factors
Cause(s)
Symptoms
Signs, Tests
Prognosis
Treatment Effect
Past Current Future
Types of question: stroke
Frequ...
What are the … outcomes (PO?)
Outcomes ?
Patients
Qualitative Research
The “best” evidence depends
on the type of question
Level Treatment Prognosis Diagnosis
I
II Randomised
trial
Inception
Co...
Level Treatment Prognosis Diagnosis
I Systematic
Review of …
Systematic
Review of …
Systematic
Review of …
II Randomised
t...
What do you do about conflicting
claims?
2. Searching: finding good answers?
Impact of searching on correctness
of answers to clinical questions
Right to
Right
Wrong to
Right
Right to
Wrong
Wrong to
...
Impact of searching on correctness
of answers to clinical questions
Right to
Right
Wrong to
Right
Right to
Wrong
Wrong to
...
3. Rapid Critical Appraisal
It’s peer-reviewed, therefore it must be OK?
Is the PICO a POEM?
Patient
Oriented
Evidence that
Matters
Critical Appraisal Steps
Did you find good quality studies?
Two steps
1.What is the PICO (Question)
2.Is the potential bia...
Use the RAMMbo to check validity
Was the Study valid?
1. Representativeness
 Who did the subjects represent?
1. Allocatio...
Fundamental Equation of Error
 Measure = Truth + Bias + Random Error
Use
good study
design
Use
large numbers
Researcher
C...
Two methods of assessing the role
of chance
 P-values (Hypothesis Testing)
 use statistical test to examine the ‘null’
h...
Step 4: Applying to the individual
 What do the results mean on average?
 What do they mean for this individual?
Applying research requires both “Whether to” and
“How to”
 “Whether to”
 Evidence quality
 Individual applicability
 “...
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Why bother with evidence-based practice?

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An introduction to evidence-based medicine (EBM) with short section in history and why EBM? Then a brief overview of the 4 steps of EBM.
These slides have been used for starting a 1-day workshops in EBM

Published in: Health & Medicine, Education
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  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • Sackett DL, Rosenberg WMC, Gray JAM, Haynes RB, Richardson WS: Evidence based medicine: what it is and what it isn’t. BMJ 1996;312:71-2. This definition of what EBM is and isn’t has gained wide acceptance and made it easier for us to get our points across.
  • G:\CREBP\Training\EBM Workshops\Unnecessary Procedures.mp4 PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice An ideal information system would be able to answer – or tell us there is no answer – to any clinical question arising in practice. Studies of doctors and students performance on searching tasks suggest there is considerable room for improvement. Table 1 summarises 3 studies that assessed subjects answers both before and after searching. Overall answers improved but in 7 to 14% of cases answers went from right to wrong, that is, the search mislead subjects. And in 36 to 48% of cases wrong answers were not improved. The problem is one of both the information systems and the system user. Most clinicians are poorly trained in structuring questions and searching. An examination of the search terms used by the TRIP search engine showed most searches used a single term and rarely used explicit Boolean connectors.
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice An ideal information system would be able to answer – or tell us there is no answer – to any clinical question arising in practice. Studies of doctors and students performance on searching tasks suggest there is considerable room for improvement. Table 1 summarises 3 studies that assessed subjects answers both before and after searching. Overall answers improved but in 7 to 14% of cases answers went from right to wrong, that is, the search mislead subjects. And in 36 to 48% of cases wrong answers were not improved. The problem is one of both the information systems and the system user. Most clinicians are poorly trained in structuring questions and searching. An examination of the search terms used by the TRIP search engine showed most searches used a single term and rarely used explicit Boolean connectors.
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • PRESENTATION ONE 05/08/13 Introduction to Evidence-Based Practice
  • Why bother with evidence-based practice?

    1. 1. Why bother with Evidence-Based Practice? Professor Paul Glasziou Bond University www.crebp.net.au/ www.testingtreatments.org Free pdf: Ch 5, 6, 7
    2. 2. Introductory Lecture: Objectives What is Evidence-Based Medicine? The steps of doing EBM 1. Formulate Clinical Questions 2. Search for Evidence 3. Appraisal of research 4. Apply to clinical problem
    3. 3. What is Evidence-Based Medicine? “Evidence-based medicine is the integration of best research evidence with clinical expertise and patient values” - Dave Sackett Patient Concerns Clinical Expertise Best ResearchSackett DL, Rosenberg WMC, Gray JAM, Haynes RB, Richardson WS: Evidence based medicine: what it is and what it isn’t. BMJ 1996;312:71-2.
    4. 4. “EBM” - birth of a term Update of CMAJ series on how to read a paper JAMA User guides 1991 authors seek a new term Clinical epidemiology? Scientific medicine? Evidence-based medicine!
    5. 5. The need for Evidence Vertebroplasty for osteoporotic fractures Gray et al Spine 2008. Nation-wide and State-specific primary vertebroplasty rates per 100,000 Part B fee-for-service Steady rise in use of vertebroplasty for a decade 2009: two large trials publish showing no effect over placebo Slides courtesy R Buchbinder
    6. 6. Unnecessary Procedures http://www.cbsnews.com/8301-18563_162-5217954.html Please click on the black screen to view the video
    7. 7. that did not work  Vertebroplasty for osteoporotic fractures (NEJM, 2010)  Arthoscopic knee lavage (Moseley, NEJM, 2002)  Blood glucose monitoring for non-insulin dependent diabetes (DiGEM trial, BMJ 2007)  Tight control of diabetes (ACCORD, NEJM, 2010)  Prostate cancer screening (Djulbegovic, BMJ 2010)  Ovarian cancer screening (JAMA, 2011)
    8. 8. Most medical innovations don’t work an analysis of 136 trials in myeloma New Treatment Better New Treatment Worse
    9. 9. How can we find the research that will improve the care of our patients? 0 500000 1000000 1500000 2000000 2500000 Biomedical MEDLINE Trials Diagnostic? MedicalArticlesperYear 5,000? per day 1,500 per day 95 per day MedicalArticlesPerYear 19 of 20
    10. 10. What should you believe?
    11. 11. Keeping up to date What is your JASPA* score? * (Journal Associated Score of Personal Angst) J: Are you ambivalent about renewing your JOURNAL subscriptions? A: Do you feel ANGER towards prolific authors? S: Do you ever use journals to help you SLEEP? P: Are you surrounded by PILES of PERIODICALS? A: Do you feel ANXIOUS when journals arrive? *Modified from: BMJ 1995;311:1666-1668 0 (?liar) 1-3 (normal range) >3 (sick; at risk for polythenia gravis and related conditions)
    12. 12. Coping with the overload: three possible things you might try A. Read an evidence-based abstraction journal (and cancel other journals) B. Keep a logbook of your own clinical questions C. Run a case-discussion journal club with your practice
    13. 13. Part 2: The 4 steps of “pull” EBM 1. Formulate an answerable question 2. Track down the best evidence 3. Critically appraise the evidence 4. Individualise, based clinical expertise and patient concerns
    14. 14. Step 1 Formulate an answerable clinical question Structure of researchable questions – PICO-T  Population/Patients  Intervention  Comparison  Outcome  Time
    15. 15. Formulating answerable clinical questions Structure of researchable questions – PICO-T  Population/Patients  Outcome
    16. 16. What are your clinical questions?  A 35 year old man says his brother recently died of a ruptured cerebral aneurysm. He is worried about whether he might have one and what the chances are that it would rupture. -> PICO Table
    17. 17. Risk Factors Cause(s) Symptoms Signs, Tests Prognosis Treatment Effect Past Current Future Types of question: stroke Frequency Cohort Study SurveyInception Cohort Study Treatments Randomised Trial CT Scan Cross Sectional Study
    18. 18. What are the … outcomes (PO?) Outcomes ? Patients Qualitative Research
    19. 19. The “best” evidence depends on the type of question Level Treatment Prognosis Diagnosis I II Randomised trial Inception Cohort Cross sectional III
    20. 20. Level Treatment Prognosis Diagnosis I Systematic Review of … Systematic Review of … Systematic Review of … II Randomised trial Inception Cohort Cross sectional III The “best” evidence depends on the type of question
    21. 21. What do you do about conflicting claims?
    22. 22. 2. Searching: finding good answers?
    23. 23. Impact of searching on correctness of answers to clinical questions Right to Right Wrong to Right Right to Wrong Wrong to Wrong McKibbon (GP or IM) 28% 13% 11% 48%
    24. 24. Impact of searching on correctness of answers to clinical questions Right to Right Wrong to Right Right to Wrong Wrong to Wrong McKibbon (GP or IM) 28% 13% 11% 48% Quick Clinical (GPs) 21% 32% 7% 40% Hersh (Med students) 20% 31% 12% 36% Hersh (Nursing) 18% 17% 14% 52%
    25. 25. 3. Rapid Critical Appraisal It’s peer-reviewed, therefore it must be OK?
    26. 26. Is the PICO a POEM? Patient Oriented Evidence that Matters
    27. 27. Critical Appraisal Steps Did you find good quality studies? Two steps 1.What is the PICO (Question) 2.Is the potential bias low? • “RAMMbo” (Valid Study?) • “FAITH” (Valid Review?)
    28. 28. Use the RAMMbo to check validity Was the Study valid? 1. Representativeness  Who did the subjects represent? 1. Allocation  Was the assignment to treatments randomised? 1. Maintainence  Were the groups treated equally? 1. Measurements blinded OR objective  Were patients and clinicians “blinded” to treatment? OR  Were measurements objective & standardised? Modified from: User Guide. JAMA, 1993
    29. 29. Fundamental Equation of Error  Measure = Truth + Bias + Random Error Use good study design Use large numbers Researcher Critically Appraise Design Confidence Intervals and P-values Reader
    30. 30. Two methods of assessing the role of chance  P-values (Hypothesis Testing)  use statistical test to examine the ‘null’ hypothesis  associated with “p values” - if p<0.05 then result is statistically significant  Confidence Intervals (Estimation)  estimates the range of values that is likely to include the true value Relationship between p-values and confidence intervals - if the value corresponding to ‘no effect’ (RR of 1 or treatment difference of 0) falls outside the CI then the result is statistically significant
    31. 31. Step 4: Applying to the individual  What do the results mean on average?  What do they mean for this individual?
    32. 32. Applying research requires both “Whether to” and “How to”  “Whether to”  Evidence quality  Individual applicability  “How to”  What & where?  How long & how often? BMJ 2003; 327 : 135

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