Below are some notes which I hope may be
helpful to
you in gaining an understanding of evidence-based medicine and the
contribution
of the Cochrane Collaboration. You will find additional resources on my
public
health page.
Here is a very broad search on public health and
evidence-based medicine
using PubMed
Archie Cochrane and the Cochrane Library
Archie Cochrane, a physician and
humanitarian (1909-1988),
strongly advocated producing systematic reviews of the medical
literature
as a way of creating "evidence-based medicine." He
believed
it was not humanly possible for a clinician to keep abreast of the
volumes
of information that were being generated and summarized this concern in
his famous statement, "It is surely a great criticism of our profession
that we have not organized a critical summary, by specialty or
subspecialty,
adapted periodically, of all relevant randomized controlled trials." He
envisioned an organization which existed for the sole purpose of
conducting
these systematic reviews in every aspect of medicine. A systematic
review
is a systematic assembly of the results of studies which use methods
that
minimize bias and random error.
In 1993, Archie Cochrane's dream came true with the
establishment of
the Cochrane Collaboration. The Cochrane Collaboration is comprised of
health care providers, consumers, and scientists who volunteer time to
compile up-to-date systematic reviews of evidence. These reviews are
published
quarterly in the Cochrane library, The purpose of the Cochrane
Collaboration
is to prepare, maintain and disseminate systematic reviews of
randomised
controlled trials (RCTs). Prior to its establishment the vast amount of
clinically important information gathered through RCTs often failed to
influence clinical practice. This was because of the enormity of the
undertaking
for any individual to collate research findings dispersed through the
world
literature in a number of languages and covering several decades.
For additional information click
here
The Ten Principles of the Cochrane Collaboration
(extracted from the
Cochrane
Collaboration Brochure )
The Cochrane Collaboration has evolved rapidly since it was
inaugurated
at the 1st Colloquium, but its basic objectives and principles have
remained the same as they were at its inception. It
is an international organization that aims to help people make
well informed decisions about health care by preparing, maintaining
and ensuring the accessibility of systematic reviews of the effects of
health care interventions. The Collaboration is being built
on nine principles:
- collaboration
- building on the enthusiasm of
individuals
- avoiding duplication
- minimizing bias
- keeping up to date
- ensuring relevance
- ensuring access
- continually improving the quality
of its work
- continuity
Definitions of Terms
This is the definition of
evidence-based
medicine
provided in the Medline thesaurus.
The process of systematically finding, appraising, and using
contemporaneous
research findings as the basis for clinical decisions. Evidence-based
medicine
asks questions, finds and appraises the relevant data, and harnesses
that
information for everyday clinical practice. Evidence-based medicine
follows
four steps: formulate a clear clinical question from a patient's
problem;
search the literature for relevant clinical articles; evaluate
(critically
appraise) the evidence for its validity and usefulness; implement
useful
findings in clinical practice. The term "evidence based medicine" (no
hyphen)
was coined at McMaster Medical School in Canada in the 1980's to label
this clinical learning strategy, which people at the school had been
developing
for over a decade. (From BMJ 1995;310:1122)
Below is a succinct description of systematic
reviews from Undertaking
Systematic Reviews of Research on Effectiveness (CRD Report no. 4)
"Systematic reviews locate, appraise and
synthesise
evidence from scientific studies in order to provide informative
empirical
answers to scientific research questions. They are therefore valuable
sources
of information for decision makers. In addition, by identifying what we
know and don't know, they are an invaluable first step before carrying
out new primary research. Systematic reviews differ from other types of
review in that they adhere to a strict scientific design in order to
make
them more comprehensive, to minimise the chance of bias, and so ensure
their reliability. Rather than reflecting the views of the authors or
being
based on only a (possibly biased) selection of the published
literature,
they contain a comprehensive summary of the available evidence."
Randomised Controlled Trials
Central to the Cochrane methodology and
evidence
based medicine is the randomised controlled clinical trial.
CONSORT (Consolidated
Standards of Reporting Trials) comprises a checklist and flow
diagram to help improve the quality of reports of randomized controlled
trials. It offers a standard way for researchers to report trials.
The Cochrane Library
The Cochrane Library consists of a number
of databases,
and these are described in detail at the National
Institute of Clinical Studies site.
Books on Evidence-Based Medicine held by the Library
Click
here to see a list of books on evidence-based medicine held by the
library. The list appears in order by title, but may be resorted by
publication
date, or by author.
Journal Articles of Interest
Dickersin
K.
, Scherer R., Lefebvre C. Systematic Reviews: Identifying relevant
studies
for systematic reviews.
BMJ 1994; 309:1286-91.
Check the appendix at the end of the
article
for the optimally sensitive Medline search strategy for identifying
randomised
clinical trials.
And finally, from the BMJ -Sacred
Cows: to the abattoir! Down with EBM! and EBM:
Unmasking the ugly truth Yes the promoters of evidence-based
methods
do have a sense of humour!