Evidence-Based Medicine (EBM)

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Evidence-Based Medicine (EBM)
Médecine Factuelle
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C-EBLM(IFCC-LM)(Cochrane, )
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Evidence-Based Nursing,
Evidence-Based Health-Care,
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Evidence-Based Management,
Evidence-Based Policy,
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Evidence-Based Sociology,
Evidence-Based History,
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Evidence-Based Mathematics,
X
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(EB)M chaque décision médicale se fonde sur
1) niveaux de preuve (les plus élevés)
2) expertise clinique (professionnelle/scientifiqu
e)
3) choix des patients
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Prejudice-, Belief-, Faith-, Tradition-,
Ideology-, Authority-, Anarchy-Based Medicine,
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Prejudice-based Medicine
Fowler FJ Jr, McNaughton Collins M, Albertsen PC,
Zietman A, Elliott DB, Barry MJ. Comparison of
recommendations by urologists and radiation
oncologists for treatment of clinically localized
prostate cancer. JAMA 20002833217-22.
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The quality of health care delivered to adults in
the United StatesMcGlynn EA, Asch SM, Adams J,
Keesey J, Hicks J, DeCristofaro A, Kerr EA.N
Engl J Med 2003 Jun 26 348(26)2635-45.
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Study Design

• - 439 indicators of quality of care for 30 acute
  and chronic conditions, and preventive care
• - Telephone survey
• - Informed consent to examine their medical
  records interview
• - Random sample of 6712 adults from 12
  metropolitan areas

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Examples of quality indicators
Hypertension Change in treatment when blood pressure is persistently high
Coronary artery disease Beta-blockers after myocardial infarction
Counselling on smoking cessation
Treatment of high LDL cholesterol levels
Colorectal cancer Screening for high-risk patients (genetics, colonoscopy)
Screening in persons at average risk (FOBT)


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Recommended care received

Medication 68,6
Immunization 65,7
Physical examination 62,9
Laboratory testing or radiography 61,7
Surgery 56,9
History 43,4
Counselling or education 18,3
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Recommended care received

• 85 Influenzae vaccination gt65y

45 MI-beta-blockers
38 Colorectal cancer/FOBT
24 HbA1c X3/y
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Conclusions
patients received 54.9 (54.3-55.5) of
recommended care
strategies to reduce these deficits are
warranted
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Strategies?EBM?
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Niveaux de preuve?

• I - Randomised Trials
• II - Non -randomised Trials, Cohort studies
• III - Case-control studies, case-reports
• IV Expert opinion

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Annual biomedicalliterature 17 000 books 2
000 000 articles(in Medline200 000 articles)
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The medical literature can be compared to
ajungle.
It is fast growing, full of dead wood,
sprinkled with hidden treasure,
and infested withspiders and snakes
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Systematic Reviews (Revues Méthodiques)

• la pierre angulaire de lEBM

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Systematic Review
(Introduction/) Question(s) (focussed) Materials
et Methods (objectivity) ? Search (systematic)
(EB-librarianship) ? Inclusion / Exclusion /
Quality assessment Results - Discussion
(limitations) (Conclusion/) Answer(s) - balance
benefits/harms (probabilités)
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Meta-analysis
- results of primary studies combined
quantitatively and statistically
- statistical power
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Trial (Year)
Mortality results from 33 trials of
beta-blockers in secondary prevention after
myocardial infarction. Adapted from Freemantle
et al BMJ 1999
Barber (1967)
Reynolds (1972)
Wilhelmsson
(1974)
Ahlmark
(1974)
Multicentre
International (1975)
Yusuf
(1979)
Andersen (1979)
Rehnqvist
(1980)
Baber
(1980)
Wilcox
Atenolol
(1980)
Wilcox
Propanolol
(1980)
Hjalmarson
(1981)
Norwegian
Multicentre
(1981)
Hansteen
(1982)
Julian (1982)
BHAT (1982)
Taylor (1982)
Manger Cats (1983)
Rehnqvist
(1983)
Australian-Swedish (1983)
Mazur
(1984)
EIS (1984)
Salathia
(1985)
Roque
(1987)
LIT 91987)
Kaul
(1988)
Boissel
(1990)
Schwartz low risk (1992)
Schwartz high risk (1992)
SSSD (1993)
Darasz
(1995)
Basu
(1997)
Aronow
(1997)
0.80 (0.74 - 0.86)
Overall (95 CI)
0.1
0.2
0.5
1
2
5
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Relative risk
(95 confidence interval)
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Cumulative meta-analysis of 33 trials of
beta-blockers in secondary prevention after
myocardial infarction
Calculated from Freemantle et al BMJ 1999
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Publication bias
All studies conducted
All studies published
Grey literature
All studies reviewed
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Systematic reviews?Levels of evidence
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(EB) Guidelines ?Levels of evidence (I-IV)
CONSENSUS
JUDGMENT
? Strength of recommendation (A-D)
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JUDGMENT /CONSENSUS
I ? A
I ? D
IV ? D
II/III/IV ? A
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Cancer colorectal dépistage de masse - FOBT
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12 guidelines
USA (ACS, 2006) OUI
USA (AGA, 2003) OUI
UK (BSG, 2000) NON
Canada (CAG, 2004) OUI
Canada (CTFPHC, 2001) OUI
Europe (2000) OUI
USA (ICSI, 2005) OUI
USA (NCCN, 2005) OUI
Australie (NHMRC, 2000) OUI
Nouvelle Zélande (NZGG, 2004) NON
Canada (QAG, 2003) OUI
Ecosse (SIGN, 2003) NON
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8 revues systématiques dont 3 publiées en
2006-2007
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Heresbach D, Manfredi S, D'halluin PN, Bretagne
JF, Branger B. Review in depth and meta-analysis
of controlled trials on colorectal cancer
screening by faecal occult blood test. Eur J
Gastroenterol Hepatol 2006 18427-433

• Méta-analyse de 4 essais contrôlés (336 000 pts)
  (France, UK, USA, Danemark)

• Réduction de la mortalité par CCR (RR
  0.79-0.94), pendant la durée du dépistage
  uniquement (10 ans)

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Moayyedi P, Achkar E. Does fecal occult blood
testing really reduce mortality? A reanalysis of
systematic review data. Am J Gastroenterol 2006
101380-4

• Méta-analyse de 3 essais contrôlés randomisés
  (245 000 pts) (UK, USA, Danemark)

• Réduction de la mortalité par CCR (RR 0.80-0.95)

• Augmentation de la mortalité non liée au CCR (RR
  1.00-1.04, p0.015) Hypothèse FOBT vaccin
  anti-cancer?

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Hewitson P, Glasziou P, Irwig L, Towler B, Watson
E. Screening for colorectal cancer using the
faecal occult blood test, Hemoccult. Cochrane
Database Syst Rev 2007 Jan 24(1)CD001216.

• Revue systématique méta-analyse de 4 essais
  contrôlés randomisés (UK, USA, Danemark, Suède)

• Réduction de la mortalité par CCR (RR 0.78-0.90)

• Augmentation de la mortalité non liée au CCR (RR
  1.00-1.03, non significatif)

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Hewitson P, Glasziou P, Irwig L, Towler B, Watson
E. Screening for colorectal cancer using the
faecal occult blood test, Hemoccult. Cochrane
Database Syst Rev 2007 Jan 24(1)CD001216.

• Effets bénéfiques du dépistage de masse
• Réduction modeste de la mortalité par CCR
• une possible reduction de lincidence du CCR
• potentiellement, une chirurgie moins invasive

• Effets délétères du dépistage de masse
• faux-positifs conséquences psycho-sociales
• complications des colonoscopies, des faux
  négatifs
• possibilité de sur diagnostic (investigations ou
  traitements inutiles et leurs complications)

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9 YES
JUDGMENT benefits outweighs harms
VALID judgment, provided both benefits and harms
are mentioned in guidelines
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3 NO (UK, Scotland, New-Zealand)
JUDGMENT benefits may or may not outweigh harms,
but the structure of health-system does not allow
to recommend for mass-screening
VALID judgment too
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CONCLUSION

• 1) niveaux de preuve (balance bénéfices/risques)
• 2) expertise professionnelle (multi-disciplinarité
  )
• 3) choix des patients

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