The Cochrane Library consists of three major databases:

• Cochrane Database of Systematic Reviews (CDSR) - full text of all systematic reviews produced by the Cochrane Collaborations, including protocols for reviews in progress.
• Database of Abstracts of Reviews of Effects (DARE) - structured abstracts for published systematic reviews.
• Cochrane Central Register of Controlled Trials (CENTRAL) - references to published and unpublished clinical research. Approximately 30% are not in PubMed.
  

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The National Guideline Clearinghouse (NGC) is a comprehensive database of references for evidence-based clinical practice guidelines and related documents compiled by the Agency for Healthcare Research and Quality (AHRQ), in partnership with the American Medical Association (AMA) and the American Association of Health Plans (AAHP). [more info]

The American College of Physicians Physician’s Information and Education Reference (ACP PIER) is a collection of disease modules containing evidence based guidelines, which can be searched or browsed in STAT! Ref. ACP PIER condenses the evidence into an easy to use point-of-care tool.

The American College of Physicians Medicine (formerly Scientific American Medicine) is an adult primary care reference tool that provides the underlying science of a condition as well as recommended diagnosis and treatment information. ACP Medicine includes references to the most current evidence for the information it provides. It can be searched or browsed in STAT! Ref.

EPC Evidence Reports is a collection of Agency for Healthcare Research and Quality evidence based reports on diagnosis and therapy, healthcare services and technologies. Reports can be searched or browsed.