RLO: Search strategy for locating randomised controlled trials

No database will cover all publications from all health care journals and the database coverage will depend on the topic. Many studies may be published in technical reports discussion papers or other formats and these may not be included in the major databases and journals, however some may be indexed on databases such as SIGLE or the National Technical Information Service or the British National Bibliography for Report Literature.

It is also important to identify ongoing trials and you can do this by going to the controlled trials register to identify published and unpublished clinical trials