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Abstract

In the early 1980s, extracorporeal shock wave lithotripsy (ESWL) was introduced not only in research but also in clinical practice, by Chaussy and associates. [1-3] It has been a popular technique for non-surgical treatment for most upper ureteric and renal calculi since then.

This study aimed to identify and analyze the characteristics of the highly cited articles in extracorporeal shock wave lithotripsy (ESWL) related to urological publications in the Science Citation Index (SCI) between 1991 and 2013. The analyzed aspects covered the distribution of annual production and its citations per publication, journals, countries, institutions, authors, and the top cited articles.

Results

There were 1722 publications found with the keywords ‘extracorporeal shock wave lithotripsy’ in the titles, abstracts, or keywords from the SCI from 1991 to 2013. In total, 1147 publications related to stones in the genitourinary system were analyzed in this study. Of total publications, 50% had 3 or 4 authors. The highest percentage of published documents were journal articles (81%), followed distantly by letters (5.4%). The core journal is the Journal of Urology (US). Articles were primarily written in English (93%). Authors from the US (30%) ranked highest in publication activity, followed by those from Germany (8.0%) and Turkey (7.1%). The publication rate of ESWL articles decreased steadily during the period of this study. In addition, a simulation model was applied to describe the relationship between the cumulative number of publications and year.

Conclusions

The largest number of publications originates from the US, and the journal with the greatest influence is the Journal of Urology. The annual number of publications decreased each year.

Keywords: Scientometrics, SCI, Extracorporeal Shock Wave Lithotripsy, Urology.

►Bibliometric Analysis of Extracorporeal Shock Wave Lithotripsy Research from 1991 to 2013

Guang-Dar Juang^1,2*, Su-Man Lin³, Cheng-Han Juang⁴

¹Division of Urology, Department of Surgery, Shin Kong WHS Memorial Hospital.

²School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan, ROC No 95 Wen-Chang Road, Shih-Lin District, Taipei 111, Taiwan, ROC.

³Department of anesthesiology, Taipei Veterans General Hospital and National Yang-Ming University School of Medicine, Taipei, Taiwan, Republic of China No. 201, Sec. 2, Shihpai Road, Taipei 112, Taiwan, Republic of China.

⁴Department of Pharmacy, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China.

Open surgical techniques were traditionally used for the treatment of stone disease in the kidneys. In the early 1980s, extracorporeal shock wave lithotripsy (ESWL) was introduced not only in research but also in clinical practice by Chaussy and associates. [1-3] It has been a popular technique for non-surgical treatment for most upper ureteric and renal calculi since then. This technique uses shock waves generated outside the body to disintegrate stones lying in the kidney or the ureter, thus allowing the fragments to pass out of the body in the urine.[4] In the last 3 decades, numerous scientific papers related to extracorporeal shock wave lithotripsy were published. Bibliometrics is a research method used in the library and information sciences. The number of research publications in scientific journals of any category is almost impossible to analyze. One common way of conducting bibliometric research is to use the Science Citation Index (SCI). Covering numerous medical topics, the SCI has been used for bibliometric analyses, which have included research contributions in ophthalmology[5], quantitative trends of patent ductus arteriosus treatment research[6], SARS-related publications in the early stage[7], and bibliometric analysis of homeopathy research.[8] In addition, urologic topics have also been analyzed by bibliometric methods using the MEDLINE and EMBASE biomedical databases[9], and include national biases in citations in urology journals.[10]

Our purpose was to study the extracorporeal shock wave lithotripsy (ESWL) research performance based on the Science Citation Index (SCI)-indexed periodicals between 1991 and 2013. These documents were analyzed and evaluated according to publication distribution and were used to determine the quantitative characteristics of extracorporeal shock wave lithotripsy research.

Materials and Methods

The 2013 edition of the Journal Citation Reports (JCR), published by the Institute for Scientific Information (ISI), lists 7509 journals in the SCI. Documents used in this study were based on the database of the SCI obtained by subscription from the ISI Web of Science, Philadelphia, PA, USA. ‘Extracorporeal shock wave lithotripsy’ was used as the keywords to search titles, abstracts, and keywords. We then categorized the search results into 5 categories, including stones in the genitourinary system, stones in the biliary system, stones in the salivary gland, stones in the musculoskeletal system, and others, which included documents with the keyword, shock wave lithotripsy (SWL), but which were not related to this study topic.

Articles, corrections, editorial materials, letters, meeting abstracts, notes, and reviews were obtained from the results of the search for document types. Articles originating from England, Scotland, Northern Ireland, and Wales were grouped under the UK heading. The impact factor (IF) of a journal was determined for each document as reported in the year 2013 JCR. Collaboration type was determined by the address of each author, where ‘independent’ was assigned if no international collaboration was presented. ‘International collaboration’ was assigned if the paper was cosigned by researchers from more than 1 country.

Results and Discussion

There were 1722 publications found with the keywords ‘extracorporeal shock wave lithotripsy’ in titles, abstracts, or keywords from the SCI from 1991 to 2013. Each paper was categorized from the title and abstract by senior professional medical surgery urological doctors. The documents were categorized into stones in the genitourinary system (1147), stones in the biliary system (357), stones in salivary glands (17), stones in the musculoskeletal system (9), and others which included documents not related to the topic in this study (192). We analyzed the 1147 documents related to stones in the genitourinary system in this study.

Documents were analyzed according to their type, language of publication, publication output, authorship, publication patterns, country of publication, and most frequently cited paper.

Type of Document

The distribution of document types identified by ISI was analyzed. From this analysis, 7 document types were found. The paper article was the most frequently used document type, comprising 81% of the total production. Letters (62, 5.4%), notes (42, 3.7%), meeting abstracts (40, 3.5%), editorial materials (39, 3.4%), reviews (28, 2.4%), and corrections (1, 0.11%) showed much-lesser significance than articles. The high distribution of articles is usually found for most topics in bibliometric analysis. For example, 73.7% of drug documents and 83.5% of surgery documents were original articles on patent ductus arteriosus treatments.[6] Analysis of Mexican scientists in the fields of biomedicine, chemistry, physics, astronomy, astrophysics, and geosciences showed that 80.5% of the total production of papers were scientific articles.[11] However, for a new research topic in the beginning stage, the distribution of articles could be much lower. Analysis of severe acute respiratory syndrome (SARS)-related research in the beginning stage showed that only 22% of documents were articles.[7]

Language of Publication

The language in which the documents were published was dominated by English (1066, 93%) followed distantly by German (39, 3.4%), French (37, 3.2%), Spanish (4, 0.34%), Russian (3, 0.26%), Italian (2, 0.17%), and Japanese (1, 0.11%). Garfield and Welljamsdorof (1992) reported that English is the main language of microbiology research, accounting for 90% - 95% of all SCI papers.[12] On the other hand, a probable reason for the high English publication distribution may be that developed countries such as the US, UK, Canada, and Australia conduct more research and have more journals published in English in SCI coverage. Publications on pediatric anesthesia also indicated a high proportion of English articles originating in the US and UK.[13] For a new research topic in the beginning stage, for example, SARS, 98% of total journal papers were published in English.[7] Moreover, from empirical evidence, there is a language bias in the coverage of the SCI, and this has consequences for international comparisons of national research performance.[14] Therefore, the high distribution of English articles on extracorporeal shock wave lithotripsy research is not surprising.

Publication Output

During the period from 1991 to 2013, the publication output steadily decreased each year (Table 1): in 1991, 115 papers were published, while in 2013, only 16 were. A correlation between the yearly cumulative number of publications and the year published was studied using mathematic models for homeopathy [8] and patent ductus arteriosus research.[6]

Table 1. Annual production of extracorporeal shock wave lithotripsy research, number of authors, and mean number of authors per paper.

Figure 1. Relationship between cumulative number of publications and year.

Figure 1 shows that a significant correlation between the yearly cumulative number of publications and the year published was made, with 2 linear relations having a high coefficient of determination. The difference in the cumulative trend was significant between the 2 periods from 1991 to 1994 and 1994 to 2013. A double logarithmic and linear plot of data for the 2 periods showed that there was a relationship between data and models with a high coefficient of determination (r² > 0.991). Logistic curve and linear fitting for the 2 periods of 1991 to 1994 and 1994 to 2013 suggested that the yearly cumulative number of publications was consistently sustained in each year. However, the yearly publications decreased each year. It can be concluded that the number of publications on research on the topic of extracorporeal shock wave lithotripsy did not grow in the study period.

These journals and the 9 journals in Zone 2 are shown in Table 3 with their impact factor, the ISI category to which they belong, the position of the journal in its category, the number of papers, and the percentage of total publications. Journals in Zone 1 may be of vital interest to extracorporeal shock wave lithotripsy research worldwide, while other journals in Zone 2 are also important because, for instance, they reflect activities in the country of a respective reader.[13] 

Table 3. Zone 1 and 2 journals with the impact factor (IF), the ISI category of the journal, the position of the journal in its category, and the number of papers (P)

1. Chaussy, C, Fuchs, G. (1985). Experience With Extracorporeal Shock-Wave Lithotripsy After 5 Years of Clinical Use. Urologe A, 24(6): 305-309.
2. Chaussy, C, Schmiedt, E. (1984). Extracorporeal Shock-Wave Lithotripsy (Eswl) For Kidney-Stones - An Alternative To Surgery. Urol Radiol, 6(2):80-87.
3. Chaussy, C, Schmiedt, E, Jocham, D, Schuller, J, Brandl, H, Liedl, B. (1984). Extracorporeal Shock-Wave Lithotripsy (Eswl) For Treatment Of Urolithiasis. Urology, 23(5): 59-66.
4. Levy, A.R, McGregor, M. (1995). How has extracorporeal shock-wave lithotripsy changed the treatment of urinary stones in Quebec? Can Med Assoc J, 153(12):1729-1736.
5. Davis, M, Wilson, C.S. (2003). Research contributions in ophthalmology: Australia's productivity. Clin Experiment Ophthalmol, 31(4): 286-293.
6. Hsieh, W.H, Chiu, W.T, Lee, Y.S, Ho, Y.S. (2004). Bibliometric analysis of patent ductus arteriosus treatments. Scientometrics, 60: 105-215.
7. Chiu, W.T, Huang, J.S, Ho, Y.S. (2004). Bibliometric analysis of severe acute respiratory syndrome-related research in the beginning stage. Scientometrics, 61: 69-77.
8. Chiu, W.T, Ho, Y.S. (2005). Bibliometric analysis of homeopathy research during the period of 1991 to 2003. Scientometrics, 63: 3-23.
9. Minozzi, S, Pistotti, V, Forni, M. (2000). Searching for rehabilitation articles on MEDLINE and EMBASE. An example is cross-over design. Arch Phys Med Rehabil, 81(6): 720-722.
10. Grange, R.I. (1999). National bias in citations in urology journals: parochialism or availability? BJU Int, 84(6): 601-603.
11. Russell, J.M. (1998). Publishing patterns of Mexican scientists: Differences between national and international papers. Scientometrics, 41: 113-124.
12. Garfield, E, Welljamsdorof, A. (1992). The Microbiology Literature - Languages Of Publication And Their Relative Citation Impact. FEMS Microbiol Lett, 100(1-3): 33-37.
13. Brambrink, A.M, Ehrler, D, Dick, W.F. (2000). Publications on pediatric anesthesia: a quantitative analysis of publication activity and international recognition. Br J Anaesth, 85(4): 556-562.
14. van Leeuwen, T.N, Moed, H.F, Tijssen, R.J.W, Visser, M.S, van Raan, A.F.J. (2001). Language biases in the coverage of the Science Citation Index and its consequences for international comparisons of national research performance. Scientometrics, 51: 335-346.
15. Lewison, G. (2002). Researchers' and users' perceptions of the relative standing of biomedical papers in different journals. Scientometrics, 53: 229-240.
16. Cunningham, S.J., Dillon, S.M. (1997). Authorship patterns in information systems. Scientometrics, 39:19-27.
17. Drenth, J.P.H. (1998). Multiple authorship - The contribution of senior authors. JAMA, 280(3): 219-221.
18. LopezMunoz, F, Boya, J, Marin, F, Calvo, J.L. (1996). Scientific research on the pineal gland and melatonin: A bibliometric study for the period 1966-1994. J Pineal Res, 20(3):115-124.
19. Marx, W, Cardona, M. (2003). The impact of Solid State Communications in view of the ISI Citation data. Solid State Commun, 127(5): 323.
20. Zetterstrom, R. (2002). Bibliometric data: a disaster for many non-American biomedical journals. Acta Paediatr, 91(10): 1020-1024.

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