There are lots of resources available to help you when designing searches.
We have put together a list of resources to use for identifying trials.
CENTRAL creation details - CENTRAL is comprised of records retrieved from PubMed/MEDLINE, Embase, ClinicalTrials.gov, KoreaMed, all Review Groups' Specialized Registers and records identified by handsearching various biomedical sources. This page on the Cochrane Library describes the process.
For both Cochrane and non-Cochrane search filters for different databases, see search filters.
- Information Retrieval Methods Group
Advice, support, and research into information retrieval techniques applicable to Cochrane systematic reviews
- Screening and Diagnostic Tests Methods Group (formerly the DTA Working Group)
DTA Handbook I Searching for DTA studies
- Expert Searching discussion list
The Cochrane Handbook (Cochrane Handbook for Systematic Reviews of Interventions: Chapter 4) provides guidance to authors for the preparation of Cochrane intervention systematic reviews including Cochrane Overviews of reviews.
The CIS Handbook (various chapters) contains links throughout to resources to help design searches, including specialised registers, the Cochrane Register of Studies and handsearching.
Methodological Expectations of Cochrane Intervention Reviews detail the agreed standards for the conduct and reporting of Cochrane Reviews of interventions.