ebm1 evidence-based medicine dr. monica hughes clinical research registrar department general...
TRANSCRIPT
EBM 1
EVIDENCE-BASED MEDICINE
Dr. Monica Hughes
Clinical Research Registrar
Department General Practice
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EBM- WHY NOW?
1) Consolidate your expertise
2) Prepare you for your job as an autonomous practitioner responsible for making decisions
3) Significant component Final MB
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LEARNING OUTCOMES
Define the term EBM
Understand the components involved in EBM
Discuss the merits of available evidence resources
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BUYING A MOBILE PHONE
• How do you choose your mobile phone????
• From where do you get reliable information????
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HOW DO WE MAKE CLINICAL DECISIONS?
• Toss a coin?
• Guess?
• Ask a friend?
• Do what your consultant tells you!
• Do no harm?
• Text books or Journals?
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HOW DO WE MAKE CLINICAL DECISIONS?
Dogma
Policy
Experiential
Whimsical
Nihilism
This is the best way to do it
This is the way we do it around here
This way worked the last few times
This way might work
It doesn’t really matter what we do
Patient deferential
Expert deferential
How would you like us to proceed?
What would you do?
Schools Of Thought……..
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WHAT IS EBM?
‘Evidence-based medicine is the process of systematically finding, appraising and
using contemporaneous research findings as the basis for clinical decision
making.’
Rosenberg 1995
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SHIFT IN PRACTICE
• Traditional Approach
– Quantity of clinical experience indicates Dr quality
– Experience of basic science is needed for decisions
– Didactic medical training is sufficient
See loads of patients, know your science and do what the consultants says
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SHIFT IN PRACTICE
• EBM Approach
– Inform all our decision making from best current evidence
– Optimises our decisions
– Allows every practitioner to formulate identical conclusions
– Accept knowledge is continually evolving –never have all the
information to answer every question
– Know how to find and formulate the information in context
Apply knowledge consistently and objectively
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SHIFT IN PRACTICE ……..WHY BOTHER?
Medicine is NOT static
• HRT & NSAIDs
Government policy
• Clinical governance & Patient safety
GMC
• Duties Of A Doctor & Revalidation
Increasingly informed Jo Public
• www. etc,
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How many minutes did you spend last week reading around your patients?
• Medical students
• PRHOs
• SHOs
• SpRs
• Consultants
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How many minutes did you spend last week reading around your patients?
• Medical students 120mins
• PRHOs
• SHOs
• SpRs
• Consultants
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• Medical students 120mins
• PRHOs 10mins
• SHOs
• SpRs
• Consultants
How many minutes did you spend last week reading around your patients?
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• Medical students 120mins
• PRHOs 10mins
• SHOs 30mins
• SpRs
• Consultants
How many minutes did you spend last week reading around your patients?
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• Medical students 120mins
• PRHOs 10mins
• SHOs 30mins
• SpRs
45mins
• Consultants
How many minutes did you spend last week reading around your patients?
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How many minutes did you spend last week reading around your patients?
• Medical students 120mins
• PRHOs 10mins
• SHOs 30mins
• SpRs
45mins
• Consultants
60mins
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ELEMENTS OF EBM
‘EBM begins and ends with patients’
EBM – The search algorithm
1) Convert patient health needs into answerable questions
2) Track down best evidence
3) Critically appraise evidence
4) Apply results to clinical practice
5) Evaluate your performance
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ELEMENTS OF EBM
‘EBM begins and ends with patients’
EBM – The search algorithm
1) Convert patient health needs into answerable questions
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Formualting Answerable questions that you can answer….
‘Answerable questions are the backbone of practising EBM’
In practice, good questions usually include:- ‘PICO’
• Patient’s clinical needs
• Intervention or exposure• Comparison intervention (if appropriate)
• Clinical Outcomes (diagnosis/prognosis/therapy/event)
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Applying the results to clinical practice….e.g. AF
• John, a retired 78yr old
gentleman is your last patient
of the day. He has a long
history of AF and is on aspirin.
He says to you ‘my friend has
atrial fibrillation and he is on
warfarin - should I be on
warfarin?’
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Applying the results to clinical practice….e.g. AF
Patient In patients with AF and who are >65….
Intervention ….would prescribing
warfarin….
Comparison ….compared to
aspirin ….
Outcome ….lead to lower
mortality or morbidity?
….. Cause any increased risk?
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Applying the results to clinical practice….e.g. AF
Stroke Risk with AF on WarfarinStroke Risk with AF on Aspirin
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Can you apply this evidence into clinical practice?
• Can the results be extrapolated to your patient?
• Availability of tests/treatment
• Affordability of tests/treatment (NB NICE etc)
• Are there adverse risks?
• Are there alternatives?
• What are the patient preferences?
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Applying the results to clinical practice…. e.g. AF
• Major bleeding risk
– Population prevalence: 10/1000
– Aspirin: Not significantly different to placebo
– Warfarin: 15/1000
• Are you going to give him warfarin?
• John is very unsteady on his feet and is prone to falls
• Are you still going to give him warfarin???
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ELEMENTS OF EBM
‘EBM begins and ends with patients’
EBM – The search algorithm
1) Convert patient health needs into answerable questions
2) Track down the best evidence
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Tracking down best evidence…..
General search strategy
• Select evidence resource
• Library/databases/guidelines/colleagues
• Design search strategy
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Tracking down best evidence…..
Hierarchy of evidence
• Systematic review
• Meta-analysis
• RCT • Cohort study Prospective e.g. Doll
• Case controlled study -Retrospective
• Cross sectional study -Snapshot
• Case series –Rare
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ELEMENTS OF EBM
‘EBM begins and ends with patients’
EBM – The search algorithm
1) Convert patient health needs into answerable questions
2) Track down the best evidence
3) Critically appraise evidence
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ELEMENTS OF EBM
‘EBM begins and ends with patients’
EBM – The search algorithm
1) Convert patient health needs into answerable questions
2) Track down the best evidence
3) Critically appraise evidence
4) Apply the results into clinical practice
EBM 39
Applying results to clinical practice….e.g. MI
• John, a retired 78yr old
gentleman is your last patient
of the day. He had an MI
2months ago and was told his
cholesterol is normal. He says
to you ‘my friend had a heart
attack and is on a drug called
a statin- should I be on this?’
EBM 40
Applying results to clinical practice…e.g. MI
Patient In patients >70 who had an MI but cholesterol is normal….
Intervention ….would adding
a statin….
Comparison ….in addition to
usual care...
Outcome ….lead to lower
mortality or morbidity
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Applying results to clinical practice…. e.g. MI
• Heart Protection Study (Lancet 2002)
– Statin therapy offers a 33% reduction in further CHD events in high risk patients EVEN when cholesterol normal or low
John should get the statin prescription
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ELEMENTS OF EBM
‘EBM begins and ends with patients’
EBM – The search algorithm
1) Convert patient health needs into answerable questions
2) Track down the best evidence
3) Critically appraise evidence
4) Apply the results into clinical practice
5) Evaluate your performance
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Evaluate Performance
Audit
Clinical efficacy
Cost analysis
Patient surveys
Prescribing rates
Referral rates
Mortality/morbidity rates
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ELEMENTS OF EBM…….. In Summary
‘EBM begins and ends with patients’
EBM – The search algorithm
1) Convert patient health needs into answerable questions
2) Track down the best evidence
3) Critically appraise evidence
4) Apply the results into clinical practice
5) Evaluate your performance
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EVIDENCE RESOURCES HIERARCHY
Most reliable -----
1] Systematic review databases
2] Review Journals
3] EBM guidelines and textbooks
4] Medline/Electronic databases
5] Opinions, texts ---least reliable
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EVIDENCE RESOURCES
1. Systematic review databases:
• The Cochrane Library:
– Best source for structured systematic reviews (SR)
– Explicit search & quality criteria
– Numerical data presented in standardized graphics enabling
quick decisions
• Database of Abstracts of Reviews of Effectiveness (DARE)
– SR structured abstracts
– Free
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EVIDENCE RESOURCES …….contd
2. Review Journals:
• Summarises systematic reviews
• Offers balanced commentary on selected papers from major
journals
Example
Evidence-Based Medicine
http://ebm.bmjjournals.com
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EVIDENCE RESOURCES …….contd
3. EBM guidelines and textbooks:
• Clinical practice guidelines
– The best sources rate the strength of evidence
• SIGN -- http://www.sign.ac.uk/
• NICE -- http://www.nice.org.uk/
– Always consider external validity to your patient
• Evidence-based textbooks
– Least detail, but most efficient source for simple queries
• Clinical Evidence is the best (explicit protocols)
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EVIDENCE RESOURCES…….contd
4. Medline/Electronic databases:
• Medline
– The largest biomedical literature database, but:
• Misses some journal articles, misclassifies others, lacks
comprehensiveness in psychology & sociology
• Can be overwhelming if not searching selectively
• PubMed
– is a free Medline service
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EVIDENCE RESOURCES …….contd
5. The least reliable:
• Colleagues or expert opinion, & “throw-away” journals
– Convenient and fast
– Often invalid , incomplete, and biased information
• Textbooks
– Generally not systematically researched
– Usually based on “expert opinion”
– Most are out of date - check for recent citations
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Some final thoughts……..
EBM
• Goal– Provide BEST patient care using current BEST evidence
• Issues– TIME required to ‘stay current’ – Research accumulating exponentially
• Challenge– Make BEST use of our limited time through
• DEVELOP information retrieval & management skills
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ON-LINE STUDENT RESOURCES
Available on
www.qub.ac.uk/cm/gp
Or
www.qub.ac.uk/qol
• Past papers
• www.qub.ac.uk/fmhs/5EBMpaper.htm
• Also see School Medicine
website for further practice
sample questions