title: Development of search strategies for systematic reviews: validation showed the noninferiority of the objective approach.
abstract: BACKGROUND
  Different approaches can be adopted for the development of search strategies of systematic reviews. The objective approach draws on already established text analysis methods for developing search filters. Our aim was to determine whether the objective approach for the development of search strategies was noninferior to the conceptual approach commonly used in Cochrane reviews (CRs).
  
  
  METHODS
  We conducted a search for CRs published in the Cochrane Library. The studies included in the CRs were searched for in MEDLINE and represented the total set. We then tested whether references previously removed could be identified via the objective approach. We also reconstructed the original search strategies from the CRs to determine why references could not be identified by the objective approach. As we performed the validation of the search strategies without study filters, we used only sensitivity as a quality measure and did not calculate precision.
  
  
  RESULTS
  The objective approach yielded a mean sensitivity of 96% based on 13 searches. The noninferiority test showed that this approach was noninferior to the conceptual approach used in the CRs (P < 0.002). An additional descriptive analysis showed that the original MEDLINE strategies could identify only 86% of all references; however, this lower sensitivity was largely due to one CR.
  
  
  CONCLUSIONS
  To the best of our knowledge, our findings indicate for the first time that the objective approach for the development of search strategies is noninferior to the conceptual approach.
authors.affiliation: Information Management Unit, Institute for Quality and Efficiency in Health Care (IQWiG), Im Mediapark 8, 50670 Cologne, Germany. Electronic address: elke.hausner@iqwig.de.
authors.forename: Elke
authors.initials: E
authors.lastname: Hausner
authors.affiliation: Department of Medical Biometry, Institute for Quality and Efficiency in Health Care, Im Mediapark 8, 50670 Cologne, Germany.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Guddat
authors.affiliation: Information Management Unit, Institute for Quality and Efficiency in Health Care (IQWiG), Im Mediapark 8, 50670 Cologne, Germany.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Hermanns
authors.affiliation: Information Management Unit, Institute for Quality and Efficiency in Health Care (IQWiG), Im Mediapark 8, 50670 Cologne, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Lampert
authors.affiliation: Information Management Unit, Institute for Quality and Efficiency in Health Care (IQWiG), Im Mediapark 8, 50670 Cologne, Germany.
authors.forename: Siw
authors.initials: S
authors.lastname: Waffenschmidt
mesh_terms: D006801:Humans; D016247:Information Storage and Retrieval / Q000379:methods* / Q000592:standards* / Q000639:trends; D011643:Publishing / Q000592:standards*; D012196:Review Literature as Topic; D057386:Search Engine / Q000592:standards*; D054928:Validation Studies as Topic
keywords: Data mining; Information storage and retrieval; Medline; Reproducibility of results; Retrospective studies; Sensitivity and specificity