title: Drug interaction databases in medical literature: transparency of ownership, funding, classification algorithms, level of documentation, and staff qualifications. A systematic review.
abstract: OBJECTIVE
  It is well documented that drug-drug interaction databases (DIDs) differ substantially with respect to classification of drug-drug interactions (DDIs). The aim of this study was to study online available transparency of ownership, funding, information, classifications, staff training, and underlying documentation of the five most commonly used open access English language-based online DIDs and the three most commonly used subscription English language-based online DIDs in the literature.
  
  
  METHODS
  We conducted a systematic literature search to identify the five most commonly used open access and the three most commonly used subscription DIDs in the medical literature. The following parameters were assessed for each of the databases: Ownership, classification of interactions, primary information sources, and staff qualification. We compared the overall proportion of yes/no answers from open access databases and subscription databases by Fisher's exact test-both prior to and after requesting missing information.
  
  
  RESULTS
  Among open access DIDs, 20/60 items could be verified from the webpage directly compared to 24/36 for the subscription DIDs (p = 0.0028). Following personal request, these numbers rose to 22/60 and 30/36, respectively (p < 0.0001). For items within the "classification of interaction" domain, proportions were 3/25 versus 11/15 available from the webpage (P = 0.0001) and 3/25 versus 15/15 (p < 0.0001) available upon personal request.
  
  
  CONCLUSIONS
  Available information on online available transparency of ownership, funding, information, classifications, staff training, and underlying documentation varies substantially among various DIDs. Open access DIDs had a statistically lower score on parameters assessed.
authors.affiliation: Clinical Pharmacology, Institute of Public Health, University of Southern Denmark, DK-5000, Odense, Denmark.
authors.forename: Gertrud Gansmo
authors.initials: GG
authors.lastname: Kongsholm
authors.affiliation: Clinical Pharmacology, Institute of Public Health, University of Southern Denmark, DK-5000, Odense, Denmark.
authors.forename: Anna Katrine Toft
authors.initials: AK
authors.lastname: Nielsen
authors.affiliation: Clinical Pharmacology, Institute of Public Health, University of Southern Denmark, DK-5000, Odense, Denmark. pdamkier@health.sdu.dk.|Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, DK-5000, Odense, Denmark. pdamkier@health.sdu.dk.
authors.forename: Per
authors.identifier: http://orcid.org/0000-0003-0591-7187
authors.initials: P
authors.lastname: Damkier
mesh_terms: D006801:Humans; D000465:Algorithms; D062313:Databases, Pharmaceutical / Q000191:economics / Q000592:standards; D004282:Documentation; D004347:Drug Interactions; D005376:Financial Management; D007318:Inservice Training
keywords: Algorithms; Classification; Documentation; Drug-drug interaction databases; Transparency