Title Place

1
Title Place

• Date

2
What Ive done / do/dont do

• Done Ive gotten out of date and retrained in
  Internal Medicine twice
• Do I run an in-patient General Medicine service
  (all comers) at a UK DGH
• 208 admissions last month
• strive to use evidence at the bedside
• Dont Ive cancelled my journal subscriptions
  (and give away the JCI and BMJ)

3
The Problems

• We need evidence (about the accuracy of
  diagnostic tests, the power of prognostic
  markers, the comparative efficacy and safety of
  interventions, etc.) about 5 times for every
  in-patient (and twice for every 3 out-patients).
• We get less than a third of it

4
The Problems

• To keep up to date in Internal Medicine, I need
  to read 17 articles a day, 365 days a year
• Need to read
• Dont
• Nor does anyone else

5
Median minutes/week spent reading about my
patients

• Self-reports at 17 Grand Rounds
• Medical Students 90 minutes
• House Officers (PGY1) 0 (up to 70none)
• SHOs (PGY2-4) 20 (up to 15none)
• Registrars 45 (up to 40none)
• Sr. Registrars 30 (up to 15none)
• Consultants
• Grad. Post 1975 45 (up to 30none)
• Grad. Pre 1975 30 (up to 40none)

6
Performance deteriorates, too

• Determinants of the clinical decision to treat
  some, but not other, hypertensives
• Level of blood pressure.
• Patients age.
• The physicians year of graduation from medical
  school.
• The amount of target-organ damage.

7
No wonder, then, that CME is growing

• Big, and getting huge.
• Usually instructionally (fact) oriented.
• Several randomised trials have shown that it does
  not improve clinical performance.

8
Three solutions

• Clinical performance can keep up to date
• by learning how to practice evidence-based
  medicine ourselves.
• by seeking and applying evidence-based medical
  summaries generated by others.
• by applying evidence-based strategies for
  changing our clinical behaviour.

9
When did EBM begin ?

• Certainly in post-revolutionary Paris.
• Arguably in B.C China.
• Some late-comers named it in 1992.

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What evidence-based medicine is

• The practice of EBM is the integration of
• individual clinical expertise
• with the
• best available external clinical evidence from
  systematic research. and
• patients values and expectations

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I.Individual Clinical Expertise

• Clinical skills and clinical judgement
• Vital for determining whether the evidence (or
  guideline) applies to the individual patient at
  all and, if so, how

12
II. Best External Evidence

• From real clinical research amongintact
  patients.
• Has a short doubling-time (10 years).
• Replaces currently accepted diagnostic tests and
  treatments with new ones that are more powerful,
  more accurate, more efficacious, and safer.

13
III. Patients Values Expectations

• Have always played a central role in determining
  whether and which interventions take place
• Were getting better at quantifying and
  integrating them

14
What EBM is not

• EBM is not cook-book medicine
• evidence needs extrapolation to my patients
  unique biology and values
• EBM is not cost-cutting medicine
• when efficacy for my patient is paramount, costs
  may rise, not fall

15
Evidence-Based MedicineThe Practice

• When caring for patients creates the need for
  information
• Translation to an answerable question
  (patient/manoeuvre/outcome).
• Efficient track-down of the best evidence
• secondary (pre-appraised) sources e.g.,
  Cochrane E-B Journals
• primary literature

16
Evidence-Based MedicineThe Practice

• Critical appraisal of the evidence for its
  validity and clinical applicability è generation
  of a 1-page summary.
• Integration of that critical appraisal with
  clinical expertise and the patients unique
  biology and beliefs è action.
• Evaluation of ones performance.

17
We neednt always carry out all 5 steps to
provide E-B Care

• Asking an answerable question.
• Searching for the best evidence.
• Critically-appraising the evidence.
• Integrating the evidence with our expertise and
  our patients unique biology and values
• evaluating our performance

18
Weve identified 3 different modes of practice

• Searching appraising
• provides E-B care, but is expensive in time and
  resources
• Searching only
• much, quicker, and if carried out among E-B
  resources, can provide E-B care
• Replicating the practice of experts
• quickest, but may not distinguish evidence-based
  from ego-based recommendations

19
Even fully EB-trained clinicians work in all 3
modes

• Searching appraising mode for the problems I
  encounter daily.
• Searching only mode among E-B resources for
  problems I encounter once a month.
• Replicating the practice of experts mode for
  problems I encounter once a decade(and crossing
  my fingers!).

20
Patients can benefit

• Even if lt10 of clinicians are capable of
  practicing in the searching appraising mode
  (5 of GPs)
• As long as most of them practice in a searching
  mode within high-quality evidence sources (70-80
  of GPs)
• Cochrane Library, E-B Journals, E-B Guidelines,
  etc

21
Three solutions

• Clinical performance can keep up to date
• by learning how to practice evidence-based
  medicine ourselves.
• by seeking and applying evidence-based medical
  summaries generated by others.
• by applying evidence-based strategies for
  changing our clinical behaviour.

22
Information required within seconds

• Systematic reviews, periodically updated, of
  randomised trials of the effects of health care
  (from all sources, and in all languages)
  The Cochrane Collaboration.

23
Cochrane Systematic Reviews (522 another 500 in
preparation) Database of Abstracts of Reviews of
Effectiveness (1895) Registry of Randomised
Controlled Trials (218,355)
24
Information required within seconds

• CD-Evidence-based journals of 2º publication
• Ê screen 50-70 clinical journals per week for
  clinical articles that pass critical appraisal
  quality filters è conclusions likely to be true.
• Ë select the subset that are clinically relevant.
• Ì summarise as more-informative abstracts.
• Í add commentaries from clinical experts.
• Î introduce with declarative titles.

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2. Seeking and Applying EBM generated by others

• Evidence-Based Medicine is published in
• English
• French
• German
• Italian
• Portuguese
• Spanish

27
2. Seeking and Applying EBM generated by others

• New Evidence-based journals of 2º publication
• E-B Cardiovascular Medicine
• E-B Health Policy Management
• E-B Nursing
• E-B Mental Health
• And as new departments in 1º journals.

28
2. Seeking and Applying EBM generated by others

• E-B Textbooks
• E-B Pain Relief
• E-B Cardiology
• includes icons for levels of evidence
• E-B On-Call
• includes gt 1300 CATs

29
Can you really practice EBM?

• Is there any E for EBM ?

30
Conventional Wisdom

• only about 15 of medical interventions are
  supported by solid scientific evidence (BMJ
  Editorial)

31
Even on the U.S. Talk-Shows (Health Outrage of
the Week)

• ..... this would put 80 to 90 per cent of
  accepted medical procedures in this country under
  the heading of quackery!

32
Problems with Conventional Wisdom

• uses clinical manoeuvres, rather than patients,
  as the denominator.
• tends to focus on high-technology, big ticket
  items.
• relies on simple literature searches that miss
  over half of the most rigorous types of
  evaluations.
• conducted from armchairs.

33
Performed an empirical study on a busy in-patient
service

• on the general medicine in-patient service of the
  Nuffield Department of Medicine at the
  Oxford-Radcliffe NHS Hospital Trust (The John
  Radcliffe)
• all our admissions arise from urgent referral
  from local GPs or via the Emergency Room

34
The Protocol

• At the time of discharge, death, or months end,
  each patient was reviewed and consensus reached
  on
• The primary diagnosis
• the disease, syndrome or condition most
  responsible for the patients admission to
  hospital

35
The Protocol (cont.)

• The Primary Intervention
• the treatment or other manoeuvre that constituted
  our most important attempt to cure, alleviate, or
  care for the primary diagnosis
• traced into the literature to determine its
  basis in evidence
• the Consultants Instant Resource Book
• bibliographic data base searches

36
Primary Interventions were Classified by Level

• Evidence from Randomised Control Trials (better
  yet systematic reviews of all relevant,
  high-quality RCTs)
• Convincing non-experimental evidence (unnecessary
  unethical to randomise)
• Interventions without substantial evidence

37
Conclusions from E-B oriented General Medicine

• 82 of our patients received evidence-based care.
• treatments for 53 were justified by RCTs or
  systematic reviews of RCTs.
• Of 28 relevant RCTs and SRs, 21 were accessible
  within seconds.
• treatments for 29 were justified by convincing
  non-experimental evidence

38
Evidence from RCTs (53)

• 36 had Cardiovascular diagnoses
• Ischaemic heart disease 17
• Heart failure 6
• Arrhythmia 2
• Thromboembolism 3
• Cerebrovascular 8

39
Evidence from RCTs (53)

• 7 had taken poison
• 5 received chemotherapy or analgesia for cancer
• 3 had gastrointestinal disorders
• 2 had obstructive airways disease

40
Convincing non-experimental evidence (29)

• Infections 15
• Cardiac disorders 7
• Miscellany (non-compliance, drug reactions, bowel
  or bladder neck obstruction, dehydration,
  micturition syncope) 7

41
Interventions without substantial evidence (18)

• Specific symptomatic and supportive care for mild
  poisoning, non-cardiac chest pain, viral
  (non-herpetic) meningitis, terminal CNS disease,
  confusion, and food poisoning.

42
Better Outcomes for Patients When EBM Is Practised

• E-B practise vs. Outcome in stroke (US)
• When cared for by E-B neurologists, patients were
  44 more likely to receive warfarin, and much
  more likely to be placed in a stroke care unit,
• And were 22 less likely to die in the next 90
  days.
  (Mitchell et al
  stroke 1996271937-43)

43
Centres for Evidence-Based Surgery

• E-B General/Vascular Unit in Liverpool
• 95 received evidence-based Rx
• 24 Level 1
• 71 Level 2
• E-B Paediatric Unit in Liverpool
• 77 received evidence-based Rx
• 11 Level 1
• 66 Level 2

44
Worse Outcomes for Patients When EBM Is Not
Practised

• In a city-wide study of E-B practise vs. Outcome
  in carotid stenosis
• Generated E-B indications for endarterectomy and
  reviewed 291 pts.
• Found the surgical indications
• Appropriate in 33
• Questionable in 49
• Inappropriate in 18

45
Worse Outcomes for Patients When EBM Is Not
Practised

• Stroke or death within the next 30 days
• Expected (if left alone) 0.5
• Expected (if properly selected and operated)
  1.5
• Observed among operated patients (2/3 operated
  for questionable or inappropriate reasons)
  gt5 Wong et al. Stroke 199728
  891-8.

46
Evidence-Based Ambulatory Paediatrics

• 54 of manoeuvres were evidence-based (experts
  had predicted lt20)
• 77 of diagnostic manoeuvres
• 67 of treatments
• 59 of health promotion

47
Centres for Evidence-Based Psychiatry

• In-Patients (Oxford)
• 67 treated on the basis of RCTs
• Out-Patient
• gt80 received evidence-based Rx

48
Evidence-Based General Practice

• 122 consecutive consultations in a suburban
  (Leeds, UK) practice.
• 81 evidence-based
• 31 based on RCTs or overviews
• 50 based on convincing non-experimental evidence
• 19 without substantial evidence (Gill et
  al, BMJ 1996312819-21)

49
Can we get evidence to the bedside?

• Need it within seconds if it is to be
  incorporated into busy clinical rounds
• Our initial attempts to bring the best evidence
  to a busy clinical team caring for 200
  admissions per month

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Searching for Evidence in the Month Before the
Cart

• Expected searches 98
• Identified searching needs 72
• Only 19 searches (26) carried out.

52
Contents of the Cart

• Infra-red simultaneous stethoscope with 12 remote
  receivers.
• Physical diagnosis text book and reprints (JAMA
  Rational Clinical Exam).
• Notebook computer, computer projector, and
  pop-out screen.
• Rapid printer.
  

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Contents of the Cart (cont)Library Round-Trip
7 min

• 125 summaries (1-3 pp) of evidence previously
  appraised and summarised by Side A teams (in the
  form of Redbook entries or Critically-Appraised
  Topics CATs).
• Access Time to the bottom line 12 sec.

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Contents of the Cart (cont)Library Round-Trip
7 min

• CD of Best Evidence
• Access Time to the bottom line 26 sec.
• CD of WinSPIRS (5-year clinical subsets)
• Access Time to useful abstract 90 sec.
  (so used for filling Educational Rx after rounds)
• CD of the Cochrane Library
  (used for filling Educational Rx after rounds)

60
Usefulness of the Cart

• 81 of searches were for evidence that could
  affect diagnostic and/or treatment decisions.
• 90 of these searches were successful in finding
  useful evidence.
• 
  

61
Of the successful searches (from the perspective
of the most junior responsible team member)

• 52 confirmed diagnostic and/or management
  decisions
• 23 led to changes in existing decisions
• 25 led to additional decisions

62
Searching for Evidence in a 3-day period after
the Cart

• Expected searches 10
• Identified searching needs 41
• Only 5 searches (12) carried out.

63
Can we get evidence to the bedside?

• Yes, and it will improve patient care.
• But can we provide it in a less cumbersome form?

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EBM and Purchasing

• In harmony
• Ê When we clinicians stop doing things that are
  useless or harmful
• ËWhen we use just-as-good but less expensive
  treatments, carers, and sites for care.

66
What we could save in Oxford by switching from

• LASIX ê frusemide 90,000
• simvastatin ê cerivastatin 500,000
• TENORMIN ê atenolol 700,000
• diclofenac ê ibuprofen 1,000,000
• Total 2,290,000
• how many hips would these savings purchase?

67
EBM and Purchasing

• Still in harmony
• Ì When we spend now to save later.

68
EBM and Purchasing

• In grudging collaboration
• Í Waiting lists, once we understand the
  opportunity costs of shortening them
• its not about money
• its about what else we wont be able to do if we
  shorten them

69
EBM and Purchasing

• In conflict
• Î When we identify so strongly with a dying
  patients short-term goals that we use resources
  that we know would add more QALYs if used for
  other patients.

70
EBM and E-B Guidelines

• EBM integrates evidence, expertise, and the
  unique biology and values of individual patients.
  
• Local EB Provision ought to integrate evidence,
  expertise, and the unique biology and values of
  the local scene.

71
EBM and E-B Guidelines

• The best evidence comes from systematic reviews
  (such as Cochrane) and/or E-B journals of 2º
  publication
• Much more likely (than personal search and
  critical appraisal) to be true
• Saves the clinicians precious (scarce!) time
• Avoids error and duplication of effort

72
EBM and E-B Guidelines

• But NO systematic review can (or should try to)
  identify the 4 Bs
• Burden
• Barriers
• Behaviours
• Balance
• They can ONLY be determined at the local (or even
  patient) level

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1. Burden

• The burden of illness, disability, and untimely
  death that would occur if the evidence were NOT
  applied
• the consequences of doing nothing

74
2. Barriers

• Patient-values preferences
• Geography
• Economics
• Administration/Organisation
• Tradition
• Expert opinion

75
3. Behaviours

• The behaviours required from providers and
  patients if the evidence is applied.
• All that guidelines can do is specify the former!

76
4. Balance

• The opportunity cost of applying this guideline
  rather than some other one.

77
Killer Bs

• Burden too small to warrant action.
• Barriers ultimately down to patients values.
• Behaviours may not be achievable.
• Balance may favour another guideline over this
  one.

78
Two monumental wastes of time and energy

• First, national/international evidence-summarising
  groups prescribing how patients everywhere
  should be treated.
• Their expertise predicting the health
  consequences if you do treat.
• Their ignorance the local Bs, and whether
  killer Bs are operating.

79
Two monumental wastes of time and energy

• Second, local groups attempting to systematically
  review the evidence.
• Their expertise identifying the local Bs and
  eliminating the killer Bs
• Their ignorance searching for all relevant
  evidence Chinese performing tests for
  heterogeneity.

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Applying a study result to my patient

• Never interested in generalising
• Am interested in a special form of extrapolation
  particularising

81
Extrapolating (particularising) to my individual
patient

• First and foremost Is my patient so different
  from those in the trial that its results can make
  no contribution to my treatment decision?
• if no contribution, I restart my search
• if it could help, I need to integrate the
  evidence with my clinical expertise and my
  patients unique biology and values...

82
To add Clinical Expertise and Patients Biology
Values

• What is my patients RISK ?
• of the event the treatment strives to prevent?
• of the side-effect of treatment?
• What is my pts RESPONSIVENESS?
• What is the treatments FEASIBILITY in my
  practice/setting?
• What are my patients VALUES ?

83
To add Clinical Expertise and Patients Biology
Values

• I begin by considering Risk and Responsiveness
  for the event I hope to prevent with the
  treatment
• The report gives me (or I can calculate) an
  Absolute Risk Reduction ARR for the average
  patient in the trial.
• ARR probability that Rx will help the average
  patient.

84
For example, Warfarin in nonvalvular atrial
fibrillation

• After 1.8 years of follow-up in an RCT
• Control Event Rate (placebo) 4.3
• Exper. Event Rate (warfarin) 0.9
• so, for the average patient in the trial, the
  probability of being helped, or Absolute Risk
  Reduction (CER - EER) 3.4 ACPJC
  199311842

85
How can I adjust that ARR for my pts Risk and
Responsiveness?

• Could try to do this in absolute terms
• my Patients Expected Event Rate PEER
• and multiply that by the RRR
• and factor in my Patients expected
  responsiveness
• Clinicians are not very accurate at estimating
  absolute Risk and Responsiveness

86
How can I adjust that ARR for my pts Risk and
Responsiveness?

• Clinicians are pretty good at estimating their
  patients relative Risk and Responsiveness
• So, I express them as decimal fractions
• frisk (if at three times the risk, frisk 3)
• fresp (if only half as responsive e.g., low
  compliance, fresp 0.5)

87
How can I adjust that ARR for my pts Risk and
Responsiveness?

• probability that Rx will help my patient ARR x
  frisk x fresp
• If ARR is 3.4
• and I judge that their frisk is 3
• and that their fresp is 0.5
• then the probability that warfarin will help my
  patient 3.4 x 3 x 0.5 5.1

88
Must also consider the probability that I will do
harm

• In the case of warfarin serious bleeding
  (requiring transfusion) from the g-i tract, or
  into the urine, soft tissues or oropharynx.
• Absolute Risk Increase 3 at 1 yr, so ARI
  estimated to be 5 in 1.8 years
  ACPJC 199412052

89
and adjust the probability of harm for my patient

• Again, can express my clinical judgement in
  relative terms fharm
• Given my patients age, I judge their fharm to
  be doubled 2
• then the probability that Rx will harm my patient
  ARI x fharm 5 x 2 10

90
Can now begin to estimate the Likelihood of Help
vs. Harm

• Probability of help ARR (embolus) x frisk x
  fresp 5.1
• Probability of harm ARI (haemorrhage) x
  fharm 10
• My patients Likelihood of Being Helped vs.
  Harmed LHH is (5.1 to 10) or 2 to 1
  against warfarin!
• or is it ?

91
The LHH has to include my patients values

• I need to take into account my patients views
  (preferences, utilities) about the relative
  severity
• of the bleed I might cause
• to the embolus I hope to prevent
• Expressed in relative terms s
• if the bleed is half as bad as the embolus, then
  s 0.5

92
On in-patient services in Oxford and Toronto

• When Dr. Sharon Straus has described a typical
  embolic stroke (with its residual disability) and
  typical moderate bleed (brief hospitalisation and
  transfusion but no permanent disability)
• for most of her patients, a bleed is only 1/5th
  as bad as a stroke
• so the s is 0.2

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So the LHH becomes

• ARR for embolus x frisk x fresp vs. ARI
  for bleed x f-harm x s
• 3.4 x 3 x 0.5 5.1 vs. 5 x 2 x 0.2
  2
• LHH 5.1 to 2 or 2.5 to1
• (I am more than twice as likely to help than harm
  my patient if they accept my offer of Rx)

94
We can work out the LHH for most patients lt6
minutes

• To be feasible on our service has to be
  do-able in 3 minutes.

95
Reactions from our patients

• All are grateful that their values/opinions are
  being sought
• 1/3 want to see the calculations, perhaps change
  their value for s, and make up their own minds.
• 1/3 adopt the LHH as presented.
• 1/3 say Whatever you tell me, doctor!