Bibliometric analysis of Spanish scienti c publications on tobacco use during the period 1970±1996

Transcription

1 European Journal of Epidemiology 15: 23±28, Ó 1999 Kluwer Academic Publishers. Printed in the Netherlands. Bibliometric analysis of Spanish scienti c publications on tobacco use during the period 1970±1996 J.A. Garcõ a-loâ pez Departamento de Farmacia y TecnologõÂa FarmaceÂutica, Facultad de Farmacia, Universidad de Granada, Spain Accepted in revised form 10 August 1998 Abstract. Spanish scienti c publications on tobacco use during the period 1970±1996 were studied, including all published work carried out in Spanish institutions indexed in IME or in MEDLINE and available on CD-ROM, using the search criteria fuma* and taba* in the rst database, and tobacco and smoking in the second. A total of 405 papers were found by IME, published in Spanish journals, and another 194 in MEDLINE, published in foreign journals. In the latter database, a time-related increase in the number of papers was detected. Original articles accounted for 80.6% of the papers analyzed. The degree of collaboration between authors, research centres and institutions was 88.6%, 30.7% and 21.8%, respectively. The most productive Spanish communities were Catalonia and Madrid. The Spanish papers were published in 83 Spanish journals, of which 36 (43.4%) published just one paper, and in 124 foreign journals, of which 85 (68.5%) published a single paper. The average number of authors per paper was in Spanish journals and in foreign ones. The total number of authors was 1633, of whom 1162 (71.2%) appeared on a single paper. The contribution of Spanish scienti c production concerning tobacco use, in international terms, has increased in recent years, but a higher level of cooperation between research centres and institutions is desirable. Key words: Authors, Bibliometrics, Journals, Papers, Spain, Tobacco Introduction Since the 1950s, numerous studies have proven statistically signi cant associations between tobacco consumption and a series of diseases and health-related issues, increasing the mortality rate [1], leading to premature deaths and a reduction in the quality of life re ected in increased health-care costs [2]. Faced with the seriousness of this problem, and considering it to be the health risk most susceptible to prevention, most developed countries have put into practice plans to reduce tobacco usage, following the long-standing recommendations of the World Health Organization [3], and have encouraged research in this eld as a matter of the highest priority [4]. The evaluation of scienti c research is a necessary task, the goal of which is to determine, and where possible improve, its e cacy. As such research plays a crucial role in a country's economic prosperity and welfare, the limited resources available should be employed as e ciently as possible. Given that the outcome of scienti c activity is only known when the author communicates his ndings to a publication distributed among the scienti c community, bibliometric indicators are of great importance. One of the systems most widely used to evaluate the scienti c production of a country within a particular research area is the analysis of the papers included in databases. In Spain, together with the Spanish Medical Index (Indice Me dico EspanÄ ol, IME), the most accessible and widely used international database is Index Medicus (MEDLINE), which is consulted for studies of various research elds [5, 6], and has been shown to be a highly suitable tool for Spanish bibliometric studies in the eld of medical science [7]. This study analyzes the published output of Spanish research into tobacco use during the period 1970±1996, on the basis of the papers contained in the IME and MEDLINE databases. Materials and methods An analysis was made of research into tobacco use, carried out in Spain and published in Spanish and foreign journals. The papers published in Spanish journals were located in the IME database, available on CD-ROM, for the period 1970±1995, using a search based on the descriptors fuma* and taba*. A manual selection was then performed to isolate the papers actually related to tobacco use describing work carried out in Spanish research centres. The papers published in foreign journals were located with the MEDLINE database, available on CD-ROM, covering the period from January 1982 to January 1997, using the descriptors tobacco and

2 24 smoking, and requiring the address eld to include Spain, Espana (MEDLINE does not recognize EspanÄ a), Espagne, Spagna or Spanien. In order not to overlook papers in which the country of origin of the research does not feature in the above eld, a careful search was also made by Spanish provinces and autonomous communities. Following this, a manual selection was made to obtain the papers actually related to tobacco use describing work carried out in Spanish research centres. The following variables were obtained from each of the selected papers: year of publication, document type, journal title, country of publication, number and description of participating centres, number and description of participating institutions, autonomous community of the principal author, number and name of authors. The number and description of participating centres and institutions is not provided for the papers located by MEDLINE, as this database only includes the research centre of the rstnamed author. From these data, the following indicators of production were calculated: productivity index (decimal logarithm of the number of papers); insularity index (percentage of authors published in only one paper); number of documents published, per year, document type, journal, country of publication, centre, institution and autonomous community. An analysis was made of the t of the distribution of authors to Lotka's law [8], which states that the number of authors (A n ) publishing n documents is inversely proportional to n 2, i.e. that the graphic representation of the number of authors versus the number of papers published corresponds to an equation of the type A n ˆ A 1 á n )2. The indicators of collaboration determined were those of co-authorship (percentage of papers produced by more than one author) and the collaboration index between centres or between institutions (the percentage of papers in which more than one centre or institution participated). The data were processed with a personal computer, using the Statgraphic 7.0 statistical program, provided by the University of Granada. The qualitative variables are expressed as absolute and relative frequencies, while the quantitative variables are expressed as the arithmetic mean the standard deviation. Table 1. Number (%) of papers located by IME (Spanish journals) and by MEDLINE (foreign journals), by years Years IME MEDLINE Total PI (1.0) ± 4 (0.7) (0.7) 0 (0.0) 3 (0.5) (0.5) 0 (0.0) 2 (0.3) (0.7) 0 (0.0) 3 (0.5) (1.7) 0 (0.0) 7 (1.2) (2.5) 0 (0.0) 10 (1.7) (7.9) 0 (0.0) 32 (5.3) (4.4) 0 (0.0) 18 (3.0) (8.1) 5 (2.6) 38 (6.3) (10.4) 7 (3.6) 49 (8.2) (14.1) 9 (4.6) 66 (11.0) (12.1) 10 (5.2) 59 (9.9) (6.2) 25 (12.9) 50 (8.3) (4.2) 24 (12.4) 41 (6.8) (6.7) 22 (11.3) 49 (8.2) (5.7) 37 (19.1) 60 (10.0) (13.1) 38 (19.6) 91 (15.2) ± 17 (8.8) 17 (2.8) 1.2 Total 405 (100) 194 (100) 599 (100) PI: productivity index. The IME database extracted 405 papers edited in Spain dealing with tobacco use investigated in Spain, while MEDLINE provided another 194 studies published in foreign journals. Table 1 illustrates the year on year distribution of these studies. MEDLINE extracted 554 papers, of which 279 were excluded because these had been published in Spanish journals, 45 more because they did not speci cally address the question of tobacco use, and 36 others because the research was carried out in foreign cities with the same name as Spanish cities. Of the 599 resulting papers, 483 (80.6%) corresponded to original articles, 48 (8.0%) to communications and addresses to congresses, 30 (5.0%) to follow-up articles and 38 (6.4%) to other document types such as editorials, letters to the editor and clinical cases. The research centre did not appear in 34 (8.4%) papers of the 405 located by IME, while a single centre was named in 257 (63.4%) papers (Figure 1), thus producing an index of collaboration between centres of 30.7%. The number of participating centres was 539, of which 487 were identi ed; the publication frequency of these is given in Table 2. The participating institution was not identi ed in 34 (8.4%) of the 405 papers found in the IME, while a single institution was named in 290 (71.6%) of the Results Figure 1. Percentage of papers located by IME, by number of participating centres.

3 25 Table 2. Centres named in papers published in Spanish journals Centres N (%) Bronchopneumology Service 33 (6.8) Department of Preventive Medicine 28 (5.7) Department of Pathology 25 (5.1) Pathology Service 24 (4.9) Cardiology Service 20 (4.1) Department of Psychology 16 (3.3) Department of Paediatrics 13 (2.7) Preventive Medicine Service 13 (2.7) Department of Biostatistics 12 (2.5) Digestive Service 10 (2.1) Department of Pharmacology 9 (1.8) Family and Community Medicine Unit 9 (1.8) Other centres (154) 275 (56.5) Total 487 (100) published papers (Figure 2), thus producing an interinstitution collaboration index of 21.8%. In all, 481 institutions participated, of which 453 were identi ed; the publication frequency of these is given in Table 3. The Clinical Hospital of Zaragoza, Barcelona Municipal Institute of Hygiene and the Medicine Faculty of Zaragoza were the predominant. The most-frequently cited institution was the Hospital, appearing on 220 (48.6%) occasions, followed by the University on 141 (31.1%), government bodies on 54 (11.9%) and other institutions on 38 (8.4%) occasions. The most productive autonomous communities were Catalonia and Madrid, which featured in 61.7% of the foreign journals (Figure 3). Among the Spanish journals, the most noteworthy were Medicina ClõÂnica (Barcelona), which published 54 (13.3%) papers (Table 4), while 36 (43.4%) of the journals published just one paper. Of the foreign journals, the American Journal of Epidemiology, Chest and the European Journal of Epidemiology were outstanding (Table 5), while 85 (68.5%) of the journals published only one paper. The foreign journals were edited in 16 di erent countries, chief among which were the USA and the UK, with 38.7% and 28.4% of papers, respectively (Table 6). Table 3. Institutions named in papers published in Spanish journals Institutions N (%) Clinical Hospital of Zaragoza 22 (4.9) Barcelona Municipal Institute of Hygiene 17 (3.8) Medicine Faculty of Zaragoza 16 (3.5) Medicine Faculty of Ca diz 10 (2.2) Medicine Faculty of Madrid 10 (2.2) ``La Paz'' Hospital, Madrid 8 (1.8) University Clinic of Pamplona 8 (1.8) ``San Pablo'' Hospital, Barcelona 8 (1.8) Medicine Faculty of Barcelona 7 (1.5) Medicine Faculty of Valencia 7 (1.5) Catalan Regional Government 7 (1.5) Clinical Hospital of Madrid 7 (1.5) Santiago de Compostela University 7 (1.5) Public Health Administration (20) 30 (6.6) Other institutions (153) 289 (63.8) Total 453 (100) Figure 3. Percentage of papers published, by the automous community of the rst-named author. Table 4. Journals containing the papers extracted by IME Journals N (%) Medicina Clõ nica 54 (13.3) Atencio n Primaria 36 (8.9) Archivos de Bronconeumologõ a 32 (7.9) Revista Clõ nica EspanÄ ola 29 (7.2) Revista EspanÄ ola de Salud Pu blica 21 (5.2) Revista EspanÄ ola de Cardiologõ a 17 (4.2) Revista EspanÄ ola de Drogodependencias 17 (4.2) Anales de Medicina Interna 16 (4.0) Anales EspanÄ oles de Pediatrõ a 15 (3.7) Gaceta Sanitaria 12 (3.0) Others (73) 156 (38.5) Total 405 (100) Figure 2. Percentage of papers located by IME, by number of participating institutions. Of the 405 papers located by IME, 64 (15.8%) had a single author, producing a co-authorship index of 84.2%. However, of the 194 papers located by

4 26 Table 5. Journals containing the papers extracted by MEDLINE Journals N (%) American Journal of Epidemiology 6 (3.1) Chest 6 (3.1) European Journal of Epidemiology 6 (3.1) Archivos del Instituto de Cardiologõ a de 4 (2.1) Me xico International Journal of Epidemiology 4 (2.1) Psychological Reports 4 (2.1) Others (118) 164 (84.5) Total 194 (100) Table 6. Distribution of papers published in foreign journals, by country of publication Country N (%) USA 75 (38.7) United Kingdom 55 (28.4) Netherlands 11 (5.7) France 10 (5.2) Italy 9 (4.6) Switzerland 8 (4.1) Denmark 6 (3.1) Others (9) 20 (10.3) Total 194 (100) MEDLINE, only 4 (2.1%) had a single author, and thus the co-authorship index in this case was 97.9% (Figure 4). Of the total of 599 papers, 68 (11.4%) had a single author, and thus the overall co-authorship index was 88.6%. The papers located by IME presented a total of 1631 signatures, varying between 1 and 20 per paper, with a mean of , and a median equal to the mode of 4. Among the papers located by MEDLINE, there were 963 signatures, varying between 1 and 14 per paper, with a mean of and a median Table 7. Author production category, by number of papers published Category Papers Authors PI Occasional (71.2) 0 Small 2±5 433 (26.5) 0 < PI < 0.7 Medium 6±9 30 (1.8) 0.7 < PI < 1 Large >9 8 (0.5) > 1 Total 1± (100) 0 < PI < 1.2 PI: productivity index. equal to the mode of 5. In neither case was any timerelated trend detected. In all, 1633 authors were cited on 2594 occasions; the distribution of these authors per number of articles published (Table 7) corresponds to an exponential curve described by the equation A n ˆ 1374 á n )2.6 (Figure 5). Discussion The issue of tobacco use has been widely studied in recent decades. Although many studies have been carried out in Spain to analyze publications by particular medical elds, such as genetics [5], drug dependency [6] and pharmacology [9], no speci c analysis has been made of publications dealing with tobacco use, with the exception of one study analyzing the books on tobacco use edited in Spain [10]. Therefore, the present study may provide an original contribution to Spanish publications on tobacco use. The results of this study should be interpreted taking into account the limitations inherent in the databases employed [11], although certain problems were avoided by using both a national database (IME) and an international one (MEDLINE). The search process within MEDLINE was performed using the word Spain in various languages, together with the titles of the autonomous communities and the provinces; this procedure provides a more real- Figure 4. Percentage of papers published, by number of authors. Figure 5. Relation of number of authors to papers published.

5 27 istic picture of a particular area of scienti c activity than the simple term Spain to describe the author's origin. Using only Spain, or the same in various languages, produced 60.2% and 64.8%, respectively, of the total number of papers obtained by the abovedescribed process. The rst entry in the IME database on research into tobacco use carried out in Spain dates from The number of papers published varied from one year to another, which might be attributed to changes in the criteria for inclusion in the database rather than variations in Spanish production in this eld. The rst entry in the MEDLINE database on research into tobacco use carried out in Spain dates from Over time, an increasing number of papers are included, which suggests a growing interest in this subject in Spain. The decrease recorded for 1996 is due to the fact that, when the search was performed, in January 1997, the papers published in 1996 had not yet been completely indexed. There is a notably widespread dispersion of centres researching the eld of tobacco use, which is indicative of the multidisciplinary nature of the subject. Nevertheless, the single most common centre was that of the Bronchopneumology Service. The most productive institutions were the Hospitals, which participated in almost half of the papers published, on the contrary to the ndings of other authors [6, 11] who, when studying other scienti c elds, identi ed the Universities as producing the greatest quantity of research materials for publication. This contrast between di erent research elds is probably related to their particular characteristics. It is also a noteworthy fact that a very large number of Institutions are investigating the eld of tobacco use. The index of collaboration is a valuable indication of the links and communication existing between researchers, and also illustrates the degree of interdisciplinary research [12]. The degree of collaboration between authors, as described by the percentage of co-authored papers and the mean number of authors per paper, was found to be high, particularly in the foreign journals. However, the degree of collaboration between centres and institutions was low, as found in previous studies of other research elds [13, 14]. This fact suggests there is little communication between di erent research teams, and therefore that the encouragement of collaboration between centres and institutions is desirable. The production of Spanish authors on tobacco use ts Lotka's law, producing an insularity index of 71.2%. This decreases for research elds or countries where scienti c activity is well consolidated. The high value of this index, con rmed by other studies [15] suggests that most published research consists of sporadic, short-term investigation. The Lotka's equation for other Spanish research elds is A n ˆ 1268 á n )3.0 [13]. As is the case for other research elds [6, 16], the most productive autonomous communities were Catalonia and Madrid, which is assumed to be related to the location in these parts of the country of greater numbers of centres or work groups investigating the eld of tobacco use. Concerning the papers published in foreign journals, the production of the community of Catalonia is double that of Madrid. This may be because, in general, the hospitals were the most productive institution and it has been shown [16] that Catalonia predominates in hospital-based medical research. There is a marked variety of journals publishing the research carried out in Spain, even more so in foreign than in Spanish journals; this dispersion also occurs in other research elds [5]. It has been concluded that such dispersion of publications tends to reduce the quality of research published [17]. The predominance of the USA and the UK, which together account for over half of all Spanish production in foreign journals, is a measure of the in uence of these countries and of the English language on Spanish research, as remarked by other authors [18]. In conclusion, although the presence of Spanish scienti c research into tobacco use, at an international level, has increased in recent years, the existence of stable groups investigating this eld is still relatively infrequent in Spain, though this does not preclude the production of high quality contributions. References 1. Peto R, Lo pez A, Bore J, et al. Mortality from tobacco in developed countries: indirect estimation from national statistics. Lancet 1992; 339: 1268± Rodrõ guez R, Buero A, Pueyos A, et al. Morbilidad, mortalidad y anä os potenciales de vida perdidos atribuibles al tabaco. Med Clin (Barc) 1996; 108: 121± Organizacio n Mundial de la Salud. La lucha contra la epidemia del tabaquismo. Serie de Informes Te cnicos no Ginebra, Ministerio de Sanidad y Consumo. Estrategias de Salud para Todos en EspanÄ a en el anä o Madrid, Martõ n C, Sanz E. Produccio n cientõâ ca espanä ola en el aâ rea de geneâ tica. Rev Esp Doc Cient 1996; 19: 377± Guardiola E, Sa nchez J. Ana lisis de la produccioâ n cientõâ ca espanä ola en dependencia de drogas. Med Clin (Barc) 1993; 101: 368± PestanÄ a A. El MEDLINE como fuente de informacioâ n bibliomeâ trica de la produccioâ n espanä ola en biomedicina y ciencias meâ dicas. Comparacio n con el Science Citation Index. Med Clin (Barc) 1997; 109: 506± Lo pez JM, Terrada ML. Los indicadores bibliomeâ tricos y la evaluacioâ n de la actividad meâ dico-cientõâ ca (II). La comunicacioâ n cientõâ ca en las distintas aâ reas de

6 28 las ciencias meâ dicas. Med Clin (Barc) 1992; 98: 101± Bordons M, Garcõ a F, Barrigo n S. Bibliometric analysis of publications of Spanish pharmacologists in the SCI (1984±89). Part I. Scientometrics 1992; 24: 163± Guardiola E, Sa nchez L. Libros publicados en EspanÄ a sobre tabaquismo. Arch Bronconeumol 1996; 32: 535± Go mez I, Sanz E, Me ndez A. Utility of bibliometric analysis for research policy: A case study of Spanish research in neuroscience. Res Policy 1990; 19: 457± Me ndez A, Go mez I, Rivas P. La investigacioâ n espanä ola en farmacologõâ a y farmacia frente al plan nacional. Mundo Cientõ co 1990; 10: 62± Alvarez M, Lo pez ML, Cueto A. Indicadores bibliomeâ tricos de la investigacioâ n en atencioâ n primaria (1988±1992). Aten Primaria 1996; 18: 229± Jime nez J, Carre MC, Argimo n JM. Tipos de estudios publicados en la revista AtencioÂn Primaria (1984± 1990). Aten Primaria 1993; 1: 23± Lopez JM, Terrada ML. Los indicadores bibliomeâ tricos y la evaluacioâ n de la actividad meâ dico-cientõâ ca (III). Los indicadores de produccioâ n, circulacioâ n y dispersioâ n, consumo de la informacioâ n y repercusioâ n. Med Clin (Barc) 1992; 98: 142± Pestala A. Quie n es quieâ n en ciencias de la vida en EspanÄ a? Mundo Cientõ co 1990; 10: 1200± Lawani SM. Some bibliometric correlates of quality in scienti c research. Scientometrics 1986; 9: 13± Navarro FA. El idioma de la medicina a traveâ s de las referencias bibliograâ cas de los artõâ culos originales publicados en Medicina ClõÂnica durante cincuenta anä os (1945±1995). Med Clin (Barc) 1996; 107: 608±613. Address for correspondence: Jose Antonio Garcõ a-loâ pez, Departamento de Farmacia y Tecnologõ a Farmace utica, Facultad de Farmacia, Campus de Cartuja s/n Granada, Spain Phone: ; Fax: jagarcia@platon.ugr.es