title: An Analysis of Altmetrics in Emergency Medicine.
abstract: OBJECTIVE
  Alternative-level metrics (Altmetrics) are a new method to assess the sharing and spread of scientific knowledge. The primary objective of this study was to describe the traditional metrics and Altmetric scores of the 50 most frequently cited articles published in emergency medicine (EM) journals. Since many articles related to EM are published in other journals, the secondary aim of this study was to describe the Altmetric scores of the most frequently cited articles relevant to EM in other biomedical journals.
  
  
  METHODS
  A structured search of the Institute for Scientific Information Web of Science version of the Science Citation Index Expanded was conducted. The 200 most frequently cited articles in the top 10 EM journals (2011 Journal Citation Report) were identified. The 200 most frequently cited articles from the rest of the medical literature, matching a predefined list of keywords relevant to the specialty of EM, were identified. Two authors reviewed the lists of citations for relevance to EM and a consensus approach was used to arrive at the final lists of the top 50 cited articles. The Altmetric scores for the top 50 cited articles in EM and other journals were determined. Descriptive statistics and Spearman correlation were performed.
  
  
  RESULTS
  The highest Altmetric score for EM articles was 25.0; the mean (±SD) was 1.9 (±5.0). The EM journal with the highest mean article Altmetric score was Resuscitation. The main clinical areas shared for articles from EM articles were trauma (mean ± SD = 11.0 ± 15.6, median = 11.0) and cardiac arrest (mean ± SD = 2.7 ± 5.8, median = 0). The highest Altmetric score for other journals was 176.0 (mean ± SD = 23.3 ± 40.8). The other journal with the highest mean article Altmetric score was the New England Journal of Medicine. The main clinical areas shared for articles were critical care (mean ± SD score = 36.5 ± 47.4, median = 36.5), sepsis (mean ± SD = 24.6 ± 48.8, median = 12.0), cardiology (mean ± SD = 19.2 ± 35.6, median = 7.0), and infectious diseases (mean ± SD = 17.0 ± 12.7, median = 17.0). Spearman correlation demonstrated weakly positive correlation between citation counts and Altmetric scores for EM articles and other journals.
  
  
  CONCLUSIONS
  This study is the first analysis of Altmetric scores for the top cited articles in EM. We demonstrated that there is a mild correlation between citation counts and Altmetric scores for the top papers in EM and other biomedical journals. We also demonstrated that there is a gap between the sharing of the top articles in EM journals and those related to EM in other biomedical journals. Future research to explore this relationship and its temporal trends will benefit the understanding of the reach and dissemination of EM research within the scientific community and society in general.
authors.affiliation: Department of Emergency Medicine, St Paul's Hospital, and the University of British Columbia, Vancouver, BC, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Barbic
authors.affiliation: Royal College Emergency Medicine Residency Program, University of Toronto, Toronto, ON, Canada.
authors.forename: Michelle
authors.initials: M
authors.lastname: Tubman
authors.affiliation: Library Services, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
authors.forename: Henry
authors.initials: H
authors.lastname: Lam
authors.affiliation: Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Skye
authors.initials: S
authors.lastname: Barbic
mesh_terms: D015706:Bibliometrics; D004635:Emergency Medicine / Q000706:statistics & numerical data*; D006801:Humans; D033181:Information Dissemination / Q000379:methods*; D055811:Journal Impact Factor