title: Worldwide research productivity in the field of electronic cigarette: a bibliometric analysis.
abstract: BACKGROUND
  Electronic cigarette (EC) is an emerging phenomenon that is becoming increasingly popular with smokers worldwide. There is a lack of data concerning the evaluation of research productivity in the field of EC originating from the world. The main objectives of this study were to analyse worldwide research output in EC field, and to examine the authorship pattern and the citations retrieved from the Scopus database.
  
  
  METHODS
  Data were searched for documents with specific words regarding EC as "keywords" in the title. Scientific output was evaluated based on the methodology developed and used in other bibliometric studies by investigation: (a) total and trends of contributions in EC research during all previous years up to the date of data analysis (June 13, 2014); (b) authorship patterns and research productivity; (c) countries contribution; and (d) citations received by the publications.
  
  
  RESULTS
  Three hundred and fifty-six documents were retrieved comprising 31.5% original journal articles, 16% letters to the editor, 7.9% review articles, and 44.6% documents that were classified as other types of publications, such as notes or editorials or opinions. The retrieved documents were published in 162 peer-reviewed journals. All retrieved documents were published from 27 countries. the largest number of publications in the field of EC was from the United States of America (USA); (33.7%), followed by the United Kingdom (UK); (11.5%), and Italy (8.1%). The total number of citations at the time of data analysis was 2.277, with an average of 6.4 citations per document and median (interquartile range) of 0.0 (0.0-5.0). The h-index of the retrieved documents was 27. The most productive institutions were Food and Drug Administration, USA (4.2% of total publications) followed by Universita degli Studi di Catania, Italy (3.9%), University of California, San Francisco, USA (3.7%).
  
  
  CONCLUSIONS
  This bibliometric study is a testament to the progress in EC research from the world over the last few years. More effort is needed to bridge the gap in EC-based research and to promote better evaluation of EC, risks, health effects, or control services worldwide.
authors: Poison Control and Drug Information Center (PCDIC), College of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine. saedzyoud@yahoo.com.
authors: Sa'ed H
authors: SH
authors: Zyoud
authors: Samah W
authors: SW
authors: Al-Jabi
authors: Waleed M
authors: WM
authors: Sweileh
mesh_terms: D015706:Bibliometrics; D035843:Biomedical Research / Q000706:statistics & numerical data*; D016208:Databases, Factual; D066300:Electronic Nicotine Delivery Systems; D006801:Humans; D007558:Italy; D006113:United Kingdom; D014481:United States