3.4.3.2 Identifying trials and developing a Specialised Register

A good review requires the identification of as many studies relevant to its topic as possible. Fields support the review process by searching their specialist sources, identifying reports of studies that appear to meet the Cochrane criteria for controlled trials (irrespective of their subject matter), and making them accessible to The Cochrane Collaboration through CENTRAL. At the same time, Fields also provide a valuable service for their own dimension of health care by establishing and developing a specialised register of randomized controlled trials (RCTs) drawn from CENTRAL, containing all the RCTs relevant to its area of interest that have been identified by The Cochrane Collaboration and others, and by ensuring its publication in The Cochrane Library.

Identifying trials

Fields are responsible for co-ordinating the searches within their specialty for studies meeting the Cochrane criteria for inclusion in the Cochrane Central Register of Controlled Trials (CENTRAL).* This entails instigating and co-ordinating:

• full text (‘hand searches’) of journals
• electronic searches of specialist databases
• searches of specialist grey literature (e.g. conference abstracts and proceedings, pharmaceutical industry, university theses)
• searches for unpublished trials

*For a more detailed account of how to co-ordinate searches, readers are invited to access the Cochrane Handsearch Manual on the Collaboration’s website.

Developing a Specialised Register

Identifying reports of trials relevant to its dimension of health care and making them accessible through specialised registers within the Cochrane Central Register of Controlled Trials (CENTRAL) is a core requirement of Fields.

The construction of an authoritative register of randomized controlled trials tailored to the needs of a particular dimension of health care establishes a valuable resource. There is no need for individuals who are in the process of forming a Cochrane Field to wait until the Field has been registered with The Cochrane Collaboration before assembling a register of randomized controlled trials. This essential task can and should be pursued concurrently with efforts to establish a Cochrane Field in their dimension of health care. A substantial and reliable Register of Trials establishes the Field’s credibility amongst its professional peers, legitimises its position as a key source for evidence for individuals and organisations who have an interest in the conduct of literature searches for RCTs and may offer the first material benefit for users of The Cochrane Library seeking helpful information related to its particular area of care.

[For a good description of the steps taken by a Field to assemble a specialised register of RCTs, see Silagy C. Developing a register of randomised controlled trials in primary health care. BMJ 1993; 306:897-900.]