Cochrane Collaboration
Encyclopedia
The Cochrane Collaboration is a group of over 28,000 volunteers in more than 100 countries who review the effects of health care interventions tested in biomedical randomized controlled trial
s. A few more recent reviews have also studied the results of non-randomized, observational studies
. The results of these systematic review
s are published as "Cochrane Reviews" in the Cochrane Library
.
of Cochrane Collaboration illustrates a meta analysis of data from seven randomized controlled trials (RCTs), comparing one health care treatment with a placebo
in a forest plot
. The diagram shows the results of a systematic review
and meta analysis on inexpensive course of corticosteroid
given to women about to give birth
too early – the evidence on effectiveness that would have been revealed had the available RCTs been reviewed systematically a decade later. This treatment reduces the odds
of the babies of such women dying from the complications of immaturity by 30–50%. Because no systematic review of these trials had been published until 1989, most obstetricians had not realised that the treatment was so effective and therefore many premature babies have probably suffered or died unnecessarily.
. It was developed in response to Archie Cochrane
's call for up-to-date, systematic reviews of all relevant randomized controlled trials of health care.
Cochrane's suggestion that the methods used to prepare and maintain reviews of controlled trials in pregnancy and childbirth should be applied more widely was taken up by the Research and Development Programme, initiated to support the United Kingdom's National Health Service
. Through the NHS R&D programme, led by the first Director of Research and Development Professor Michael Peckham
, funds were provided to establish a 'Cochrane Centre', to collaborate with others, in the UK and elsewhere, to facilitate systematic reviews of randomized controlled trials across all areas of health care..
The principles of the Cochrane Collaboration are:
Randomized controlled trial
A randomized controlled trial is a type of scientific experiment - a form of clinical trial - most commonly used in testing the safety and efficacy or effectiveness of healthcare services or health technologies A randomized controlled trial (RCT) is a type of scientific experiment - a form of...
s. A few more recent reviews have also studied the results of non-randomized, observational studies
Observational study
In epidemiology and statistics, an observational study draws inferences about the possible effect of a treatment on subjects, where the assignment of subjects into a treated group versus a control group is outside the control of the investigator...
. The results of these systematic review
Systematic review
A systematic review is a literature review focused on a research question that tries to identify, appraise, select and synthesize all high quality research evidence relevant to that question. Systematic reviews of high-quality randomized controlled trials are crucial to evidence-based medicine...
s are published as "Cochrane Reviews" in the Cochrane Library
Cochrane Library
The Cochrane Library is a collection of databases in medicine and other healthcare specialties provided by the Cochrane Collaboration and other organisations. At its core is the collection of Cochrane Reviews, a database of systematic reviews and meta-analyses which summarize and interpret the...
.
Logo
The logoLogo
A logo is a graphic mark or emblem commonly used by commercial enterprises, organizations and even individuals to aid and promote instant public recognition...
of Cochrane Collaboration illustrates a meta analysis of data from seven randomized controlled trials (RCTs), comparing one health care treatment with a placebo
Placebo
A placebo is a simulated or otherwise medically ineffectual treatment for a disease or other medical condition intended to deceive the recipient...
in a forest plot
Forest plot
A forest plot is a graphical display designed to illustrate the relative strength of treatment effects in multiple quantitative scientific studies addressing the same question. It was developed for use in medical research as a means of graphically representing a meta-analysis of the results of...
. The diagram shows the results of a systematic review
Systematic review
A systematic review is a literature review focused on a research question that tries to identify, appraise, select and synthesize all high quality research evidence relevant to that question. Systematic reviews of high-quality randomized controlled trials are crucial to evidence-based medicine...
and meta analysis on inexpensive course of corticosteroid
Corticosteroid
Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex. Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte...
given to women about to give birth
Birth
Birth is the act or process of bearing or bringing forth offspring. The offspring is brought forth from the mother. The time of human birth is defined as the time at which the fetus comes out of the mother's womb into the world...
too early – the evidence on effectiveness that would have been revealed had the available RCTs been reviewed systematically a decade later. This treatment reduces the odds
Odds
The odds in favor of an event or a proposition are expressed as the ratio of a pair of integers, which is the ratio of the probability that an event will happen to the probability that it will not happen...
of the babies of such women dying from the complications of immaturity by 30–50%. Because no systematic review of these trials had been published until 1989, most obstetricians had not realised that the treatment was so effective and therefore many premature babies have probably suffered or died unnecessarily.
History
The Cochrane Collaboration was founded in 1993 under the leadership of Iain ChalmersIain Chalmers
Sir Iain Chalmers is a British health services researcher, one of the founders of the Cochrane Collaboration, and coordinator of the James Lind Initiative, which includes the James Lind Library and James Lind Alliance....
. It was developed in response to Archie Cochrane
Archie Cochrane
Archibald Leman Cochrane was a Scottish doctor whose name is synonymous with scientific method in medicine.-Biography:Cochrane was born in Kirklands, Galashiels, Scotland...
's call for up-to-date, systematic reviews of all relevant randomized controlled trials of health care.
Cochrane's suggestion that the methods used to prepare and maintain reviews of controlled trials in pregnancy and childbirth should be applied more widely was taken up by the Research and Development Programme, initiated to support the United Kingdom's National Health Service
National Health Service
The National Health Service is the shared name of three of the four publicly funded healthcare systems in the United Kingdom. They provide a comprehensive range of health services, the vast majority of which are free at the point of use to residents of the United Kingdom...
. Through the NHS R&D programme, led by the first Director of Research and Development Professor Michael Peckham
Michael Peckham
Sir Michael Peckham is a British oncologist and artist. As a cancer physician he is best known for his contribution to the treatment of testicular cancer...
, funds were provided to establish a 'Cochrane Centre', to collaborate with others, in the UK and elsewhere, to facilitate systematic reviews of randomized controlled trials across all areas of health care..
In October 1995, The Collaboration formed the Cochrane Consumer Network to incorporate patient perspectives into the review process. Shortly thereafter, new 'plain language summaries' provided users with a jargon-free synopsis of each systematic review.
Goal and principles
The goal of the collaboration is 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 principles of the Cochrane Collaboration are:
- collaboration
- "building on the enthusiasm of individuals"
- avoiding duplication
- minimizing bias
- keeping up to date
- striving for relevance
- promoting access
- ensuring quality
- continuity
- enabling wide participation
Criticism
A 2011 study done to disclose possible conflicts of interests in underlying research studies used for medical meta-analyses reviewed 29 meta-analyses and found that conflicts of interests in the studies underlying the meta-analyses were rarely disclosed. The 29 meta-analyses included 11 from general medicine journals; 15 from specialty medicine journals, and 3 from the Cochrane Database of Systematic Reviews. The 29 meta-analyses reviewed an aggregate of 509 randomized controlled trials (RCTs). Of these, 318 RCTs reported funding sources with 219 (69%) industry funded. 132 of the 509 RCTs reported author conflict of interest [COI] disclosures, with 91 studies (69%) disclosing industry financial ties with one or more authors. The information was, however, seldom reflected in the meta-analyses. Only two (7%) reported RCT funding sources and none reported RCT author-industry ties. The authors concluded “without acknowledgement of COI due to industry funding or author industry financial ties from RCTs included in meta-analyses, readers’ understanding and appraisal of the evidence from the meta-analysis may be compromised.” Noting that most assessment tools for meta-analysis do not include a domain for study funding source the authors state: “Currently, The Cochrane Collaboration’s Risk of Bias tool includes an optional 'other sources of bias' domain, which meta-analysts could use to include information on COIs. We recommend that The Cochrane Collaboration consider formalizing the requirement to assess potential bias from COIs.”See also
- Evidence-based medicineEvidence-based medicineEvidence-based medicine or evidence-based practice aims to apply the best available evidence gained from the scientific method to clinical decision making. It seeks to assess the strength of evidence of the risks and benefits of treatments and diagnostic tests...
- Cochrane LibraryCochrane LibraryThe Cochrane Library is a collection of databases in medicine and other healthcare specialties provided by the Cochrane Collaboration and other organisations. At its core is the collection of Cochrane Reviews, a database of systematic reviews and meta-analyses which summarize and interpret the...
- Systematic reviewSystematic reviewA systematic review is a literature review focused on a research question that tries to identify, appraise, select and synthesize all high quality research evidence relevant to that question. Systematic reviews of high-quality randomized controlled trials are crucial to evidence-based medicine...
- Cochrane Consumer Network