evidence-based medicine ( ebm ) = médecine factuelle
TRANSCRIPT
Evidence-Based Medicine (EBM)
=Médecine Factuelle
C-EBLM
(IFCC-LM)(Cochrane, …)
Evidence-Based Nursing,
Evidence-Based Health-Care, …
Evidence-Based Policy, …
Evidence-Based Management,
Evidence-Based Sociology,
Evidence-Based History, …
Evidence-Based
Mathematics, …X
(EB)M = chaque décision médicale
se fonde sur:1) niveaux de preuve (les plus
élevés)2) expertise clinique
(professionnelle/scientifique)
3) choix des patients
Prejudice-, Belief-, Faith-, Tradition-, Ideology-,
Authority-, Anarchy-Based Medicine, …
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 2000;283:3217-22.
The quality of health care delivered to
adults in the United States
McGlynn EA, Asch SM, Adams J, Keesey J, Hicks J, DeCristofaro A, Kerr EA.
N Engl J Med 2003 Jun 26; 348(26):2635-45.
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
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)
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 %
Recommended care received
Recommended care received
85%: Influenzae vaccination >65y
45%: MI-beta-blockers
38%: Colorectal cancer/FOBT
24%: HbA1c X3/y
Conclusions
• patients received 54.9% (54.3-55.5) of recommended care
• strategies to reduce these deficits are warranted
Strategies?
EBM?
Niveaux de preuve?
I - Randomised TrialsII - Non -randomised Trials, Cohort studies
III - Case-control studies, case-reports
IV – Expert opinion
Annual biomedicalliterature:
17 000 books +
2 000 000 articles
(in Medline:200 000 articles)
“The medical literature can be compared to a
jungle. It is fast growing, full of
dead wood,sprinkled with hidden
treasure,and infested with
spiders and snakes”
Systematic Reviews (Revues Méthodiques)
= la pierre angulaire de l’EBM
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)
Meta-analysis- results of primary studies combined quantitatively
and statistically
- statistical power
Relative risk
(95% confidence interval)
0.1 0.2 0.5 1 2 5 10
Trial (Year)
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)
Overall (95% CI) 0.80 (0.74 - 0.86)
Mortality results from 33
trials of beta-blockers in
secondary prevention after
myocardial infarction.
Adapted from Freemantle et al BMJ 1999
0.8 1 20.5
“ 1997 1995 1993 “ 1992 1990 1988 “ 1987 1985 “ 1984 “ “ “ “ “ “ 1982 “ 1981 “ “ “ 1980 “ 1979 1975 “ 1974 1972 1967
Year
Relative Risk (95% Confidence Interval)
Cumulative meta-analysis of 33 trials of beta-blockers in secondary prevention after myocardial infarction
Calculated from Freemantle et al BMJ 1999
Publication biasAll studies conducted All studies published
All studies reviewed
Greyliterature
Systematic reviews
↓Levels of evidence
(EB) Guidelines
↓Levels of evidence (I-IV)
CONSENSUS JUDGMENT
↓
Strength of recommendation (A-D)
JUDGMENT /CONSENSUSI → AI → D
IV → D
II/III/IV → A
Cancer colorectal
dépistage de masse - FOBT
12 guidelinesUSA (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
8 revues systématiques
dont 3 publiées en 2006-2007
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; 18:427-433
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)
Moayyedi P, Achkar E. Does fecal occult blood testing really reduce mortality? A reanalysis
of systematic review data. Am J Gastroenterol 2006; 101:380-4
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, p=0.015) [Hypothèse: FOBT = vaccin anti-cancer?]
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)
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 l’incidence 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)
9 YES:
JUDGMENT: benefits outweighs harms
VALID judgment, provided both benefits and harms are mentioned in guidelines
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
CONCLUSION1) niveaux de preuve (balance
bénéfices/risques)
2) expertise professionnelle (multi-disciplinarité)
3) choix des patients
38%