Frequently asked questions

What is a Systematic Review?

A systematic review is defined as “a review of a clearly formulated question that uses systematic and explicit methods to identify, select and critically appraise relevant research, and to collect and analyze data from the studies that are included in the review. Statistical methods ([such as] meta-analysis) may or may not be used to analyze and summarize the results of the included studies.”

For more information on the importance of and rationale for systematic reviews, please see the following article:

Rationale for systematic reviews

Another article on this topic is Get the Big Picture, with Less Bias, written by Hilda Bastian.

What is Cochrane and what does it do?

Cochrane is an international non-profit and independent organization, dedicated to making up-to-date, accurate information about the effects of healthcare readily available worldwide. It produces and disseminates systematic reviews of healthcare interventions and promotes the search for evidence in the form of clinical trials and other studies of interventions. Cochrane was founded in 1993 and named for the British epidemiologist, Archie Cochrane.

What is distinctive or important about Cochrane systematic reviews?

A Cochrane review is a systematic, up-to-date summary of reliable evidence of the benefits and risks of [a healthcare intervention]. Cochrane reviews are intended to help people make practical decisions [about healthcare]. The specific methods used in [preparing] a Cochrane review are described in the text of the review . . . [which] adheres to a structured format.” Cochrane reviews are prepared by volunteer reviewers working with Cochrane , and are published quarterly on the Cochrane Library.

Who writes systematic reviews?

Cochrane systematic reviews are prepared by people who have an interest in finding what evidence is available to answer a specific healthcare question such as “Does aspirin prevent second heart attack?” They may be healthcare professionals or consumers of healthcare; Cochrane works to support participation by anyone interested in undertaking a systematic review, regardless of their background or training.

What is the Cochrane Library?

The Cochrane Library is a collection of databases, prepared or compiled by Cochrane and other organizations focused on evidence-based healthcare research. It is published quarterly on the Internet and on CD-ROM, and is available by subscription.

What is evidence-based health care?

Evidence-based health care is “the conscientious, explicit and judicious use of current best evidence in making decisions about health care. This requires integrating individual health care expertise and the patient's circumstances and wishes with the best available external clinical evidence from systematic research and reviews on issues of diagnostic accuracy, prognosis, and the effectiveness of therapy.”

What is the role of the US Cochrane Center in Cochrane ?

The US Cochrane Center (USCC) is responsible for coordinating US involvement in the work of Cochrane . To achieve this, the USCC provides information, training, and support to people interested in the work of Cochrane, as well as to those already involved in preparing systematic reviews. The USCC also works to disseminate information about evidence-based health care and Cochrane to the US healthcare community. In addition to these roles, the USCC also coordinates Cochrane’s initiatives to undertake electronic and hand searching of healthcare literature worldwide. These initiatives are to identify reports of trials and to contribute to the development of the Cochrane Central Register of Controlled Trials, a resource for reviewers which is one of the databases published on the Cochrane Library. Further information on the USCC’s contributions to these initiatives may be found elsewhere on this website.

What is handsearching?

Cochrane defines handsearching as “the planned searching of a journal page by page (i.e. by hand), including editorials, letters, etc., to identify all reports of randomized controlled trials and controlled clinical trials . . . Trial[s] found . . . [are] coded appropriately using definitions agreed within Cochrane. All identified trials, regardless of topic, are sent to the [US Cochrane Center (USCC)] . . . for inclusion in [Cochrane Central Register of Controlled Trials] . . . A handsearching manual is available through the [USCC -- add link] and should be read before handsearching is commenced. A journal handsearch registration form must be completed for each journal title, and sent to [the USCC] to avoid duplication of effort].”

How can I contribute?

If you want more information on how to get involved in Cochrane and are based in the US, contact the US Cochrane Center (USCC):

US Cochrane Center
615 N Wolfe Street, Room E6012
Baltimore, Maryland 21205
Phone: 410- 502-4631

A member of the USCC staff will work with you to identify the best way for you to get involved and direct you to the appropriate Cochrane entity for your area of interest.

Source for all quotes is the Glossary of the Cochrane Reviewers’ Handbook:

(Source: Clarke M, Oxman AD, editors. Cochrane Handbook for Systematic Reviews of Interventions 4.2.5 [updated May 2005]. )