An Introduction to Cochrane Collaboration
and its Impact on Medical Practices
Gerd Antes
Cochrane Germany (www.cochrane.de)
University Medical Center Freiburg
REHA-Kolloquium
Frankfurt 20. März 2017
Conflicts of interest
– The Cochrane Germany is a central unit of the University
Medical Centre Freiburg
– G. Antes is 100% employed by the University Hospital
– Potential conflict:
Long-lasting commitment to Evidence and Systematic Reviews
Contents
– Evidence to answer the crucial question: What works?
– Systematic reviews as key technology for knowledge synthesis
– Cochrane as host for global knowledge and rigorous methology
Transfer of Research into Practice
Answers to medical questions
• Clinical (randomised / controlled) studies
• Epidemiological (observational -) studies
. . . .
Evid
en
ce
ap
plic
atio
n
Evid
en
cd
pro
du
ctio
n
? • Practicing physicians
• Health authorities, sickness funds, insurances, institutions
• Clinical research
• Patients
50 %
Kn
ow
led
ge T
ran
sla
ton
1968 McMaster Univ.
Hamilton, Canada
1971 Archie Cochrane, UK
1993 Cochrane Collab.
1998 Cochrane Germany
The trial deluge
194 271 355 476 649 1241 1468
2071 2550
2855
3893 4535
5647
6762
7591 8261
9490
10382 10357
11530 11164
12257
13484
15199
17360
19087
20614
22510
25333
27445
29638
29131
0
5.000
10.000
15.000
20.000
25.000
30.000
35.00019
65
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
RCTs (Reports) in Medline
Overall: 419.020
September 2016
The truth
194 271 355 476 649 1241 1468
2071 2550
2855
3893 4535
5647
6762
7591 8261
9490
10382 10357
11530 11164
12257
13484
15199
17360
19087
20614
22510
25333
27445
29638
29131
0
5.000
10.000
15.000
20.000
25.000
30.000
35.000
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
Freiburg Ethics Board
2000-2002:
48% published until 2010
J. Simes (1986)
RCTs (Reports) in Medline (PubMed)
Overall: 419.020
September 2016
Transfer of Research into Practice
Clinical studies (experimental, randomised, controlled, prospective)
Epidemiological studies (observational, retrospective)
Systematic Reviews
Health Technology Clinical Guidelines Patient Information
Assessment (HTA)
Disease Clinical
Management Programs (DMPs) Pathways (CPs)
EB
M
glo
bal
local
The knowledge refinery
„All“ trials ?
Not published Not
identified identified
?
Review
Quality?
1. Framing the question (PICO)
2. Systematic search for evidence
from relevant trials and studies
3. Critical appraisal of trials - inclusion
4. Summary and quantivative
synthesis (if possible)
5. Interpreting and putting in context
Updating!!
Produce unbiased view of “all” evidence
July 2011
Example
Thrombolysis after
acute myocardial
infarction
NEJM 1992
Forest Plot
Body of
Evidence
Cumulative Forest Plot:
Stop - Regel?
Thrombolysis (Streptokinase) after myocardial infarction NEJM 1992
Forest Plot:
Open questions
– No accepted stopping rule
– Have all relevant trials been identified and considered?
Need „all“ (!) relevant trials:
2016 no reliable method and procedure
RCTs of aprotinin in
cardiac surgery to
stop bleeding
Lancet 2005
Clinical Trials 2005
1987
2002
Cited
Benefit?
Harm?
Costs?
Research in context
Leaving things out
Selective reporting =
1. Hiding whole trials (classical publication bias)
2. Hiding (or distorting) information from trials which are published
3. Spin: Interpretations which have nothing to do with the trial results
Striving for quality:
Trial registration as basis for transparency
WHO Register Network ICTRP www.who.int/ictrp
Urology
ANZCTR
CT not WHO
Primary Registry
EU Clinical
Trials Register
Clinical
Trials.gov
DRKS
Declaration of Helsinki 2013
“Research Registration and Publication and
Dissemination of Results
35.Every research study involving human subjects
must be registered in a publicly accessible
database before recruitment of the first subject.
36.Researchers, authors, sponsors, editors and
publishers all have ethical obligations with
regard to the publication and dissemination of
the results of research. Researchers have a duty
. . . . . . . .
Trusted evidence. Informed decisions. Better health
The Cochrane Collaboration (since 1993)
Independent network of 36000+ contributors
from science and health professions
Systematic Reviews
Leading principle: Minimizing bias
Risk of Bias
Cochrane Library
Counts
September 2016
7004 reviews
2516 protocols
Impact Factor 2015:
6.103 (vorläufig)
9520 9668
Today
992236
The Cochrane Library
- free searching and abstracts
- updating system
Cochrane is
- a charity under UK law
- member of WH assembly
- organized globally in entities
<20% von Cochrane
Knowledge accumulation: backfiring?
Systems of wrong incentives, agendas driven by science and scientists‘
careers, maldevelopment of journals . . .
Commentary
M. J. Page
D. Moher
Blog Pubmed
Commons
A new enemy?
Open access, data sharing . . .
Old: The poor can‘t read
New: The poor can‘t write
A strong barrier:
language
Most frequently visited SRs
1000 lay language summaries in German
The biggest challenge: Updating
The solution?
Living Systematic Reviews: An Emerging Opportunity
to Narrow the Evidence-Practice Gap
Summary
– Systematic reviews as key technology knowledge accumulation
to provide evidence for medical decisions
– Cochrane is an international network to support the production
of systematic reviews and to develop rigorous methodology
www.globalevidencesummit.org
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