Chinese Research Status in Emergency Medicine Journals: a Bibliometric Analysis Based on Science Citation Index Expanded Database

Background. Emergency medicine in China has undergone tremendous


Introduction
Bibliometrics, first introduced by Pritchard, are an effective method for analyzing scientific production and research trends.(8) As the most important and frequently used source database for the study of scientific output, the Science Citation Index Expanded (SCIE) database from the Web of Science had widely been used for bibliometric analysis of various fields.(9)(10)(11)(12)(13)(14) Therefore, in this study, we used the bibliometric method to study the status of Chinese research and trends in emergency medicine journals based on SCIE database, during the period 2000-2013.The SIGNA VITAE 2016; 11 (1): document type, language of publication, output of different journals, and collaboration patterns were analyzed.Distribution of article titles, and keywords were studied to reveal research focuses and trends.

Materials and methods
The data used in this study were derived from the database of SCIE,  (15): the term "China independent article" was assigned if authors were all from China; the term "institutional independent" was assigned if authors were from the same institution in China; the term "internationally collaborative article" was designated if authors were from China and other countries; the term "national collaboration" was assigned if authors were from different institutions in China.The included articles were analyzed in terms of publication outputs, document type, language of publication, journals, countries/territories, institutions, title words, and keywords.The included articles were downloaded in Microsoft Excel, and additional coding was performed manually.

Publication outputs during the year 2000-2013
SIGNA VITAE 2016; 11(1): Research in emergency medicine in China started in the 1980s.Since then, publications from China can be found in international EM journals.The earliest six articles were entitled ''Dehydration therapy and hypotension in post-resuscitation cerebral edema, and application of intraocular-pressure measurement -a review of resuscitation work .1.''(16) in Resuscitation, ''On the intracardiac use of combined adrenaline, isoprenaline and noradrenaline in the resuscitation of the heart beat -a review of resuscitation .2.'' (17) in Resuscitation, ''Closed-chest intracardiac injection'' (18) in Resuscitation, ''Hemodynamic-studies of the effect of total alkaloids of datura in experimental hemorrhagic-shock in dogs'' (19) in Resuscitation, ''Large dose atropine alkaloids in the treatment of shock'' (20) in Resuscitation, and ''Experimental-study in rabbits of the antishock effect of anisodamine (654-2), and its mechanism of action'' (21)

Document type and language of publication
According to the document type classification at the Web of Science, seven document types were found among the total of 1043 publications during 2000-2013.'Journal article' was the most frequently used document type, with 754 articles, accounting for 72.3% of total productions.The other types were letters (126; 12.1%), editorial materials (92; 8.8%), reviews (41; 3.9%), meeting abstracts (20; 1.9%), proceedings paper articles (9; 0.9%) and corrections (1; 0.1%).In this study, a total of 754 journal articles were extracted from the 1043 documents for further analyses.
Languages of all articles in this study were grouped.English was the only language used for all of these articles.

Distribution of articles in journals
There were 25

Distribution of institutes and international collaborations
Contributions of institutions were identified as the participation of at least one author.The 754 journal articles were distributed among 253 Chinese affiliations.A total of 647 (85.8 %) articles were China independent publications and 107 (14.2 %) papers were international collaborations.Table 2 shows the top 20 institutes based on the number of papers.We found that 9 (45%) institutes were from Hong Kong, followed by institutes from Beijing (3; 15%).

Titlewords analysis
The title indicates what the article is about and distinguishes it from other articles.( 22) An analysis of single words in the title could be used to make inferences of the scientific literature or to identify the subjective focus and emphasis specified by authors.(23) Therefore, in this study, all single words within the title of articles were analyzed.Some prepositions and common words such as ''in'' ''of'' ''and'' ''with'' ''the'' ''a'' ''by'' ''for'' ''using" were excluded, as they have no usefulness for the analysis of are listed in table 4. We noticed that among the 784 article titles, ''Injury/Injuries'' ranked first, followed by "patient" and "emergency".
These words showed a decreasing trend with the year of publication.

'Keywords plus' analysis
Keywords plus provides additional search terms extracted from the titles of articles cited by authors in their bibliographies and footnotes in the ISI database.( 24) Keywords plus may appear in articles that have no author keywords, or may include important terms that are not listed in the titles, abstracts, or authors keywords.Distribution of keywords plus in different periods has been used to provide further information for research trends.
Several limitations to this study warrant discussion.First, the analyses may be particularly susceptible to bias and error in determining Emergency medicine (EM) in China started in the 1980s as an independent discipline.(1) Since then, EM in China has undergone tremendous growth.Up to now, emergency departments have been established in hospitals at different levels.At the same time, a large pool of specialists involving in clinical practice, research and teaching has been formed.Numerous studies (2-7) have been carried out on the various aspects of emergency medicine development in China; however, there is no report to analyze Chinese research status and trends in emergency medicine.
Reuters Web of Science, Philadelphia, USA.According to Journal Citation Reports (JCR) for 2014, it indexes 8474 journals with citation references across 176 scientific disciplines.There was a total of 25 journals in the Web of Science category of ˝emergency medicine˝.All articles from 2000 to 2013 with "Peoples R China" in the address field (updated March 1, 2014) were collected from the 25 EM journals.Articles only addressed in Taiwan were excluded from the study.Articles from England, Scotland, Northern Ireland, and Wales were reclassified as from the United Kingdom (UK).(15) The impact factor (IF) of each journal was collected from the JCR published in 2014.Contributions of different institutions and collaborated countries were estimated by the affiliation of at least one author to the article.Collaboration type was determined by the addresses of the authors in Resuscitation.During the period 2000-2013, there was a total of 1043 articles published by Chinese authors in the Web of Science for the subject category 'emergency medicine'.The cumulative numbers of articles presented an increasing trend, as shown in figure 1.Only five papers were published in 2000, while the number of papers reached 195 in 2011, about 40 times of that in 2000.The fastest-growing period was from 2007 to 2008, reaching a growth rate of 151%.SIGNA VITAE 2016; 11(1):
research trends.The top 20 most frequently used single words in the title SIGNA VITAE 2016; 11(1): eligibility and categorization of articles.A more comprehensive overview of emergency medicine research status in China would necessitate a systematic review of MEDLINE, EMBASE, and other medical libraries across a longer time frame.In conclusion, the current study on China's research performance in emergency medicine journals in SCIE database demonstrates some significant points, which can help to map emergency medicine development and research trends in China, and potentially guide Chinese EM physicians in evaluating and orienting their research.

Table 1 .
journals in the Web of Science (2014) category of 'emergency medicine'.Except Emergency Medicine Clinics of North America, Notarzt, Notfall & Rettungsmedizin, and Prehospital Emergency Care, the remaining 21 journals published different numbers of articles from China.presents the numbers of articles being published by China, their impact factors in 2013, and impact factor ranks.It is noticed that Hong Kong Journal of Emergency Medicine (HKJEM) published the most Chinese articles (240), accounting for 23% of the total, followed by International Journal of the Care of the Injured (171; 16.4%) and Journal of TraumaInjury Infection and Critical Care (149; 14.3%).

Table 1 .
Distribution of articles in journals found in the Web of Science category of 'emergency medicine' during 2000-2013.Rank, rank in order of impact factor in the Web of Science; TA (%), total number and percentage of articles.

Table 3
displays the top ten internationally collaborative countries, total number of articles collaborated with China, and the rank and percentage of first author articles and corresponding author articles.USA ranked first place, followed by Canada and Australia.

Table 3 .
Top ten internationally collaborative countries/territories during the year 2000-2013.

Table 4 .
Top 20most frequently used single words in the title, 2000-

Table 5 .
Top 20 most used keywords, 2000-2013.As for the internationally collaborative countries/territories, USA ranked first place.The reason may be that since 1978/1979, China-U.S. academic exchange has become a steady trend.According to the Institute of International Education, the number of Chinese students in the United States rose to 1000 in 1980, while in the 2012/2013 academic year, 235597 Chinese studied there.China-US academic exchange has been flourishing over the past 35 years.Currently, China is the leading place of origin for students going to the United States, while the United States is the second-biggest sender of students to China.
circles, business and the courts.Therefore, compared with authors from mainland China, authors from Hong Kong have better English, and have less difficulty in writing English, which may help them to publish articles easier in international journals.