title: The database for aggregate analysis of ClinicalTrials.gov (AACT) and subsequent regrouping by clinical specialty.
abstract: BACKGROUND
  The ClinicalTrials.gov registry provides information regarding characteristics of past, current, and planned clinical studies to patients, clinicians, and researchers; in addition, registry data are available for bulk download. However, issues related to data structure, nomenclature, and changes in data collection over time present challenges to the aggregate analysis and interpretation of these data in general and to the analysis of trials according to clinical specialty in particular. Improving usability of these data could enhance the utility of ClinicalTrials.gov as a research resource.
  The purpose of our project was twofold. First, we sought to extend the usability of ClinicalTrials.gov for research purposes by developing a database for aggregate analysis of ClinicalTrials.gov (AACT) that contains data from the 96,346 clinical trials registered as of September 27, 2010. Second, we developed and validated a methodology for annotating studies by clinical specialty, using a custom taxonomy employing Medical Subject Heading (MeSH) terms applied by an NLM algorithm, as well as MeSH terms and other disease condition terms provided by study sponsors. Clinical specialists reviewed and annotated MeSH and non-MeSH disease condition terms, and an algorithm was created to classify studies into clinical specialties based on both MeSH and non-MeSH annotations. False positives and false negatives were evaluated by comparing algorithmic classification with manual classification for three specialties.
  
  
  CONCLUSIONS
  The resulting AACT database features study design attributes parsed into discrete fields, integrated metadata, and an integrated MeSH thesaurus, and is available for download as Oracle extracts (.dmp file and text format). This publicly-accessible dataset will facilitate analysis of studies and permit detailed characterization and analysis of the U.S. clinical trials enterprise as a whole. In addition, the methodology we present for creating specialty datasets may facilitate other efforts to analyze studies by specialty groups.
authors.affiliation: Duke Clinical Research Institute, Durham, North Carolina, United States of America. asba.tasneem@duke.edu
authors.forename: Asba
authors.initials: A
authors.lastname: Tasneem
authors.forename: Laura
authors.initials: L
authors.lastname: Aberle
authors.forename: Hari
authors.initials: H
authors.lastname: Ananth
authors.forename: Swati
authors.initials: S
authors.lastname: Chakraborty
authors.forename: Karen
authors.initials: K
authors.lastname: Chiswell
authors.forename: Brian J
authors.initials: BJ
authors.lastname: McCourt
authors.forename: Ricardo
authors.initials: R
authors.lastname: Pietrobon
mesh_terms: D000465:Algorithms; D002986:Clinical Trials as Topic / Q000145:classification* / Q000706:statistics & numerical data*; D003627:Data Interpretation, Statistical; D016208:Databases, Factual; D006801:Humans; D046650:Medical Subject Headings; D008511:Medicine / Q000145:classification / Q000706:statistics & numerical data; D014481:United States