The Emtree term "diagnostic test accuracy study" retrieved less than half of the diagnostic accuracy studies in...

Embase is a biomedical and pharmacological bibliographic database of published literature, produced by Elsevier. In 2011, Embase introduced the Emtree term "diagnostic test accuracy study," after discussion with the diagnostic test accuracy (DTA) community of Cochrane. The aim of this study is to investigate the performance of this Emtree term when used to retrieve diagnostic accuracy studies.

We first piloted a random selection of 1,000 titles from Embase and then repeated the process with 1,223 studies specifically limited to humans. Two researchers independently screened those for eligibility. From titles that were indicated as being relevant or potentially relevant by at least one assessor, the full texts were retrieved and screened. A third researcher retrieved the Emtree terms for each title and checked whether "diagnostic test accuracy study" was one of the attached Emtree terms. The results of both exercises were then cross-classified, and sensitivity and specificity of the Emtree term were estimated.

Our pilot set consisted of 1,000 studies, of which 20 (2.0%) were studies from which DTA data could be extracted. Thirteen studies had the label DTA study, of which five were indeed DTA studies. The final set consisted of 1,223 studies, of which 33 (2.7%) were DTA studies. Twenty studies were labeled as DTA study, of which fourteen indeed were DTA studies. This resulted in a sensitivity of 42.4% (95% CI: 25.5% to 60.8%) and a specificity of 99.5% (95% CI: 98.9% to 99.8%).

Although we planned to include a more focused set of studies in our second attempt, the percentage of DTA studies was similar in both attempts. The DTA label failed to retrieve most of the DTA studies and 30% of the studies labeled as being DTA study were in fact not DTA studies. The Emtree term DTA study does not meet the requirements to be useful for retrieving DTA studies accurately.