title: Alternative to the Science Citation Index impact factor as an assessment of emergency medicine's scientific contributions.
abstract: OBJECTIVE
  The Science Citation Index "impact factor" is the only available quantitative estimate of a journal's scientific contributions. However, the derivation of this factor contains an intrinsic bias that underestimates the impact of emergency medicine journals. We wished to test the hypothesis that use of an alternative criterion standard would provide an improved profile of the scientific contributions of emergency medicine journals relative to those of other specialties.
  
  
  METHODS
  We used an observational, longitudinal, comparative design in which all Index Medicus citations from Advanced Cardiac Life Support (ACLS) publications were aggregated by journal and then stratified by specialty. Proportions and proportionate trends, relative to total citations, were reported by specialty, facilitating comparison of emergency medicine with other disciplines.
  
  
  RESULTS
  Among all eight ACLS publications (1974-1994) 4,062 citations met the inclusion criteria. Emergency medicine journals were referenced in 16% of eligible citations (99% confidence interval [CI], 14% to 17%), a figure exceeded only by internal medicine and cardiology journals. Emergency medicine was the only discipline to show a significant proportionate increase in contributions over the 20-year study period (P < .001 by chi 2 for linear trend analysis).
  
  
  CONCLUSIONS
  Contrary to the implications of a low impact factor, an analysis of journal citations in ACLS publications over two decades suggests that emergency medicine has made significant contributions to a broad and important area of scientific inquiry.
authors.affiliation: Department of Emergency Medicine, Albert Einstein College of Medicine, Bronx, NY, USA.
authors.forename: D P
authors.initials: DP
authors.lastname: Barnaby
authors.forename: E J
authors.initials: EJ
authors.lastname: Gallagher
mesh_terms: D015982:Bias; D015706:Bibliometrics; D004635:Emergency Medicine / Q000706:statistics & numerical data*; D008020:Life Support Care; D008523:MEDLARS; D010506:Periodicals as Topic / Q000706:statistics & numerical data*; D011643:Publishing / Q000706:statistics & numerical data*; D012013:Reference Books