Cochrane Collaboration

The Cochrane Collaboration is an international, non-profit effort to establish a database for reviews in medical intervention to ascertain efficacy of those interventions and promote the search for evidence in clinical trials. Interventions are specifically those measures that health care professionals take to alleviate illness and discomfort. The collaboration is named for the Scottish epidemiologist, Archie Cochrane whose work ultimately initiated the collaboration. Cochrane’s Rock Carling Lecture, “Effectiveness and Efficiency", given in 1972, is recognised as the initial impetus for the Cochrane Collaboration. In his Rock Carling Lecture, Cochrane delineated the “importance of randomised controlled trials (RCTs) in assessing the effectiveness of treatments”. His work subsequently led to the establishment of the Cochrane Collaboration, a global effort locating, assessing and synthesising RCTs in all areas of medicine.

Cochrane’s rationale for this project can be summed up in this excerpt:

"It is surely a great criticism of our profession that we have not organised a critical summary, by specialty or subspecialty, adapted periodically, of all relevant randomised controlled trials".

Problem and Solution

Problem

The Collaboration database is designed to address the overwhelming amount of information that is being produced by clinics and research facilities. At the beginning of the second quarter of 2007, PubMed, one of the largest medical sciences databases on Earth, had more than 16 million citations for research journals dating back to the 1950s from 33,360 journals of which more than 7,000 articles were indexed for ‘hemochromatosis’, 10,790 for ‘autism’, 47,418 for ‘spinal trauma, 575,965 for ‘virus’, and 1,059,081 for ‘gene’.

For the individual health practioner or researcher, reading, evaluating and incorporating best practices from this amount of material is unmanageable.

Solution

The Collaboration is designed allow the use of systematic reviews of the available research to:

• efficiently integrate valid information and provide a basis for rational decision making;
• establish where healthcare is consistent or varies significantly;
• allow the application of research results across populations, settings, and small differences in treatment;
• limit bias (systematic errors);
• reduce chance effects,
• provide more reliable results upon which to draw conclusions and make decisions;
• use Meta-analysis to summarise the results of independent studies for more precise estimates of the effects of healthcare (rather than those derived from the individual studies.

The Cochrane Library

The Cochrane Library is a regularly updated database comprised of collections of medically related research (evidence-based medicine), including The Cochrane Database of Systematic Reviews.The Cochrane Library, published quarterly, is available on-line or on CD-ROM by subscription through Wiley InterScience, John Wiley & Sons, Inc. and through medical libraries.

Databases

Databases included in The Cochrane Library:

• The Cochrane Database of Systematic Reviews
• The Database of Abstracts of Reviews of Effects
• The Cochrane Central Register of Controlled Trials (CENTRAL)
• The Cochrane Methodology Register
• The NHS Economic Evaluation Database
• Health Technology Assessment Database
• Cochrane Database of Methodology Reviews (CDMR)

Evidence–based medicine

Evidence–based medicine is defined as:

“the conscientious use of current best evidence in making decisions about the care of individual patients or the delivery of health services.”

“...an approach to practising medicine in which the clinician is aware of the evidence in support of clinical practice, and the strength of that evidence.”

”...the conscientious, explicit and judicious use of current best evidence in making decision about the care of individual patients...integrating individual clinical expertise with the best available external clinical evidence from systematic research.” .”

Study guidelines

Systematic review of literature is basically about finding the pertinent research reports and eliminating those that that do not reach acceptable levels of methodological rigour and then analyzing and summarizing those that do.

Guidelines from National Guideline Clearinghouse

Guidelines are established by numerous bodies that provide their methods of search and their recommendations. Examples of methodological parameters:

• Methods use to select /collect evidence (e.g. hand searches or electronic searches of publications)
• Description of methods used to collect or select evidence (i.e. who searched what sources published when)
• Inclusion Criteria (i.e. what criteria was met for acceptance or rejection)

• Relevancy to treatment questions
• Type of study (e.g. use of randomized, controlled trials, case series
• Number and type of subjects (e.g. human)
• Efficacy,
• Safety,

• Total number of sources
• Methods used to assess quality and strength of evidence (e.g. expert consensus, rating scheme)
• Methods used to analyze evidence (e.g. review of published meta-analyses)
• Method used to formulate recommendations (e.g. expert consensus)