The Cochrane Library (named after Archie Cochrane) is a collection of databases in medicine and other healthcare specialties provided by the Cochrane Collaboration and other organizations. At its core is the collection of Cochrane Reviews, a database of systematic reviews and meta-analyses which summarize and interpret the results of medical research. The Cochrane Library aims to make the results of well-conducted controlled trials readily available and is a key resource in evidence-based medicine.
Access and use
The Cochrane Library is a subscription-based database, originally published by Update Software and now published by John Wiley & Sons, Ltd as part of Wiley Online Library. In many countries, including parts of Canada, the United Kingdom, Ireland, the Scandinavian countries, New Zealand, Australia, India, South Africa, and Poland, it has been made available free to all residents by "national provision" (typically a government or Department of Health pays for the licence). There are also arrangements for free access in much of Latin America and in "low-income countries", typically via HINARI. All countries have free access to two-page abstracts of all Cochrane Reviews and to short plain-language summaries of selected articles.
Cochrane Reviews appear to be relatively underused in the United States, presumably because public access is limited (the state of Wyoming is an exception, having paid for a licence to enable free access to Cochrane Reviews for all residents of Wyoming). 
The Cochrane Library consists of the following databases:
- The Cochrane Database of Systematic Reviews (Cochrane Reviews). Contains all the peer-reviewed systematic reviews and protocols prepared by the Cochrane Review Groups.
- The Database of Abstracts of Reviews of Effects (DARE). Contains quality-assessed abstracts of systematic reviews, including a summary of the review and a critical appraisal of its overall quality.
- The Cochrane Central Register of Controlled Trials (CENTRAL). Is a database that contains details of articles of Controlled trials and other studies of healthcare interventions from bibliographic databases (majorly MEDLINE and EMBASE), and other published and unpublished sources that are difficult to access.
- The Cochrane Methodology Register (Methodology Register). Is a bibliography of publications that report on methods used in the conduct of controlled trials.
- Health Technology Assessment Database (HTA). Brings together details of completed and ongoing health technology assessments (studies of the medical, social, ethical and economic implications of healthcare interventions) from around the world.
- NHS Economic Evaluation Database (NHS EED). This database systematically identifies economic evaluations from around the world, appraises their quality, and highlights their relative strengths and weaknesses.
The Cochrane Reviews, CENTRAL, Methodology Reviews and Methodology Register are produced by the Cochrane Collaboration. DARE, HTA and NHS EED are compiled and maintained by the Centre for Reviews and Dissemination.
Cochrane Reviews take the format of full-length methodological studies. Cochrane researchers will perform searches of medical databases including MEDLINE, PubMed and EMBASE; a continually updated database of trials called the Cochrane Central Register of Controlled Trials (CENTRAL); hand searching, where researchers look through entire libraries of scientific journals by hand and; reference checking of obtained articles in order to identify studies that are relevant to the question they are attempting to answer.
The quality of each study is carefully assessed using predefined criteria and evidence of weak methodology or the possibility that a study may have been affected by bias is reported in the review.
Cochrane Researchers then apply statistical analysis to compare the data of the trials. This creates a review of studies, or systematic review, which gives the final word on the efficacy of a particular medical intervention. The result often shows a lack of evidence for a particular treatment one way or the other, recommending additional medical studies before doctors and pharmacists prescribe a particular intervention.
Finished reviews are available as a full report with diagrams, in condensed form or as a plain language summary, in order to provide for every reader of the review.
Impact factor and ranking
In the most recent Journal Citation Reports publication, The Cochrane Database of Systematic Reviews has a 2010 impact factor of 6.186, ranking it 10th among 151 journals in the category "Medicine, General & Internal".
The Cochrane Library Feedback tool allows users to provide comments on and feedback of Cochrane Reviews and Protocols in The Cochrane Library. If accepted, the feedback will be published in a scrolling list of comments in reverse chronological order, with the most recent submission at the top of the page. The Collaboration has a procedure for the event of serious error, an event which has only occurred once in its history.
- Grimes DA, Hou MY, Lopez LM, Nanda K (February 2008). "Do clinical experts rely on the Cochrane library?". Obstet Gynecol 111 (2 Pt 1): 420–2. doi:10.1097/01.AOG.0000300558.51373.ae. PMID 18238981.
- Dickersin K, Manheimer E, Wieland S, Robinson KA, Lefebvre C, McDonald S. Development of the Cochrane Collaboration’s Central Register of Controlled Clinical Trials. Eval Health Prof. 2002 Mar 1;25(1):38–64.
- "About The Cochrane Library". The Cochrane Library. Retrieved 2012-11-29.
- "Newcomer’s guide". Cochrane Library. Retrieved 2010-11-29.
- The Cochrane Collaboration. The Cochrane Manual Issue 1, 2008, section 188.8.131.52 COCHRANE LIBRARY FEEDBACK HOUSE RULES [updated 15 November 2007]. (http://www.cochrane.org/admin/manual.htm) (accessed 12 December 2007)
- Procedures to be followed in the event of serious errors in published Cochrane reviews