Rebecca Beynon, Mariska M.G. Leeflang, Steve McDonald, Anne Eisinga, Ruth L Mitchell, Penny Whiting, Julie M Glanville

A systematic and extensive search for as many eligible studies as possible is essential in any systematic review. When searching for diagnostic test accuracy (DTA) studies in bibliographic databases, it is recommended that terms for disease (target condition) are combined with terms for the diagnostic test (index test). Researchers have developed methodological filters to try to increase the precision of these searches. These consist of text words and database indexing terms and would be added to the target condition and index test searches.Efficiently identifying reports of DTA studies presents challenges because the methods are often not well reported in their titles and abstracts, suitable indexing terms may not be available and relevant indexing terms do not seem to be consistently assigned. A consequence of using search filters to identify records for diagnostic reviews is that relevant studies might be missed, while the number of irrelevant studies that need to be assessed may not be reduced. The current guidance for Cochrane DTA reviews recommends against the addition of a methodological search filter to target condition and index test search, as the only search approach.