The Cochrane hepato-biliary group as a resource example of evidence-based medicine for all.

PERSPECTIVA INTRODUCTION The Cochrane Hepato-Biliary Group (the CHBG) is a non-profit and not-for-profit independent, international, specialty research group within The Cochrane Collaboration (http://www.cochrane.org). Since its formation in 1996, The CHBG has established itself as a reliable source of evidence-based systematic reviews of interventions within the area of hepato-biliary diseases to which more than 1 600 people contribute primarily as authors, peer reviewers, and editors. The CHBG has also developed a Hepato-Biliary Controlled Trials Register containing references to about 13 500 randomised clinical trials. CHBG reviews and the Register are published in the Cochrane Library (http:// www.thecochranelibrary.com). In the seventeen year period of its existence, The CHBG has registered 448 titles for systematic reviews, has published 258 review protocols, and 153 systematic reviews. By the end of the year, another 15 protocols and 30 reviews, all of them in editorial, would be finalized. What Cochrane systematic reviews and non-Cochrane reviews and meta-analyses have in common is that they are all retrospective, observational studies. The main difference, however, is that Cochrane systematic reviews are preceded with a title registration followed by the publication of a peer reviewed protocol on The Cochrane Library. The published protocol defines the methods and the statistics for the conductance of the systematic review, thus protecting the review from bias and data-driven results while being conducted or updated. The Cochrane reviews may be on prevention, diagnosis, treatment, or care. The people involved in the production of these reviews follow the guidelines of The Cochrane Collaboration provided in The Cochrane Handbook for Systematic Reviews of Interventions