The Cochrane Library is one of the major libraries having high quality health care information, including the Cochrane Database of Systematic Reviews, from the Cochrane Collaboration. Cochrane Systematic Reviews bring together research on the effects of health care and are considered the gold standard for determining the relative effectiveness of different interventions. The Cochrane Collaboration (http://www.cochrane.org) is a UK registered international charity and the world’s leading producer of systematic Reviews. It has been demonstrated that Cochrane Systematic Reviews are of comparable or better quality and are updated more often than the reviews published in print journals (Wen J et al; The reporting quality of meta-analyses improves: a random sampling study. Journal of Clinical Epidemiology 2008; 61: 770-775).

In 2010 The Cochrane Library moved from quarterly to monthly publication.

The Cochrane Library is published by Wiley-Blackwell on behalf of the Cochrane Collaboration.

The Cochrane Library Podcasts: a collection of podcasts on a selection of Cochrane Reviews by authors of reviews in this issue will be available from www.cochrane.org/podcasts.

The Cochrane Library can be accessed at www.thecochranelibrary.com. Guest users may access abstracts and plain language summaries for all reviews in the database, and members of the media may request full access to the contents of the Library. A number of countries, including countries in the World Bank’s list of low-income economies (countries with a gross national income (GNI) per capita of less than $1000), have national provisions by which some or all of their residents are able to access The Cochrane Library for free.