EVIDENCEBASED MEDICINE

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EVIDENCE-BASED MEDICINE

• Dr. Monica Hughes
• Clinical Research Registrar
• Department General Practice

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EBM- WHY NOW?

• Consolidate your expertise
• Prepare you for your job as an autonomous
  practitioner responsible for making decisions
• 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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BUYING A MOBILE PHONE

• Would you trust the information you get from this
  salesperson????

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BUYING A MOBILE PHONE

• What about the Carphone Warehouse website?

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BUYING A MOBILE PHONE

• Would you trust what your friends say?

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BUYING A MOBILE PHONE

• What about the OFCOM website?

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STRAW POLL

• Salesperson
• Carphone Warehouse Website
• Friends
• Ofcom Website

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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?
Schools Of Thought..
Dogma ?
This is the best way to do it
Policy ?
This is the way we do it around here
Experiential ?
This way worked the last few times
Whimsical ?
This way might work
Nihilism ?
It doesnt really matter what we do
Patient deferential ?
How would you like us to proceed?
Expert deferential ?
What would you do?
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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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SHIFT IN PRACTICE ..WHY BOTHER?

• But ultimately
• EBM improves health care

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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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How many minutes did you spend last week reading
around your patients?

• Medical students 120mins
• PRHOs 10mins
• SHOs
• SpRs
• Consultants

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How many minutes did you spend last week reading
around your patients?

• Medical students 120mins
• PRHOs 10mins
• SHOs 30mins
• SpRs
• Consultants

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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

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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
• Patients clinical needs
• Intervention or exposure
• Comparison intervention (if appropriate)
• Clinical Outcomes (diagnosis/prognosis/therapy/eve
  nt)

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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 gt65.
• 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

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Applying the results to clinical practice.e.g.
AF
Stroke Risk with AF on Warfarin
Stroke 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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Critically appraising the 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

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Applying results to clinical practice.
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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?

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Applying results to clinical practicee.g. MI

• Patient In patients gt70 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

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Thanks for your attention..

• Any Questions.