Supplementary search methods versus bibliographic database searching to identify studies and study reports

This is a protocol for a Cochrane Review (methodology). The objectives are as follows: To assess the effectiveness and resource requirements of supplementary search methods compared with bibliographic database searching for identifying studies and study reports. The supplementary search methods we will consider are: citation searching; contacting study authors; handsearching; regulatory agency sources and clinical study reports; clinical trials registries; web searching.