title: National representation in the emergency medicine literature: a bibliometric analysis of highly cited journals.
abstract: OBJECTIVE
  In recent years, significant growth has been seen in the field of emergency medicine. However, the national productivity to the field of emergency medicine remains unknown. This study aimed to reveal the national contributions in the field of emergency medicine.
  
  
  METHODS
  Articles published in 13 highly cited journals in emergency medicine in 2006 to 2010 were retrieved from PubMed and Science Citation Index. The number of total articles, the per-capita numbers, impact factors (IFs), and citations were tabulated to assess the contribution of different countries.
  
  
  RESULTS
  A total number of 9775 articles were published in the 13 journals from 2006 to 2010 worldwide. West Europe, North America, and East Asia were the most productive regions. High-income countries published 87.9% of the total articles. United States published the most number of articles in 2006 to 2010 (4523/9775, or 46.3%), followed by United Kingdom, Australia, China, and Canada. Besides, United States also had the highest total IFs (8729.73) and total citations (22,117). When normalized to population size, Australia had the highest number of articles per million persons (26.00). Germany had the highest mean IF (2.27) and mean citations (6.87).
  
  
  CONCLUSIONS
  United States is the most productive country in the field of emergency medicine.
authors.affiliation: Department of Emergency Medicine, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Yuan
authors.initials: Y
authors.lastname: Jiang
authors.forename: Mao
authors.initials: M
authors.lastname: Zhang
mesh_terms: D001315:Australia; D015706:Bibliometrics; D002170:Canada; D019049:Developed Countries; D004635:Emergency Medicine / Q000706:statistics & numerical data*; D005060:Europe; D005202:Asia, Eastern; D005602:France; D010506:Periodicals as Topic / Q000706:statistics & numerical data*; D006113:United Kingdom; D014481:United States