title: Search strategies to identify reports on "off-label" drug use in EMBASE.
abstract: BACKGROUND
  Medications are frequently prescribed outside their regulatory approval (off-label) by physicians particularly where appropriate therapies are not available. However, the risk/benefit ratio of drugs in off-label use needs to be critically appraised because it may differ from approved on-label usage. Therefore, an extensive exploration of current evidence on clinical data is well-advised. The objective of this study was to develop a search strategy that facilitates detection of the off-label drug use documents in EMBASE via OvidSP.
  
  
  METHODS
  We constructed two sets of gold standards from relevant records to off-label drug use by a sensitive search of MEDLINE and EMBASE. Search queries, including search words and strings, were conceived based on definition of off-label use of medications as well as text analysis of 500 randomly selected relevant documents. The selected terms were searched in EMBASE (from 1988 to 2011) and their retrieval performance was compared with the gold standards. We developed a sensitivity-maximizing, and a sensitivity- and precision-maximizing search strategy.
  
  
  RESULTS
  From 4067 records relevant to off-label drug use in our full gold standard set, 3846 records were retrievable from EMBASE. "off label*.af." was the most sensitive single term (overall sensitivity 77.5%, sensitivity within EMBASE 81.9%, precision 88.1%). The highest sensitive search strategy was achieved by combining 36 search queries with overall sensitivity of 94.0% and precision of 69.5%. An optimal sensitive and precise search strategy was yielded precision 87.4% at the expense of decreasing overall sensitivity to 89.4%.
  
  
  CONCLUSIONS
  We developed highly sensitive search strategies to enhance the retrieval of studies on off-label drug use in OvidSP EMBASE.
authors.affiliation: Department of Clinical Pharmacology, Medical University Vienna, General Hospital, Austria.
authors.forename: Bita
authors.initials: B
authors.lastname: Mesgarpour
authors.forename: Markus
authors.initials: M
authors.lastname: Müller
authors.forename: Harald
authors.initials: H
authors.lastname: Herkner
mesh_terms: D000465:Algorithms; D016206:Databases, Bibliographic; D004348:Drug Labeling; D004358:Drug Therapy; D006801:Humans; D016247:Information Storage and Retrieval / Q000379:methods*; D016239:MEDLINE; D056687:Off-Label Use; D057386:Search Engine / Q000379:methods