Percentage Of Self-citations Research Articles

In health research publications, the number of authors is strongly associated with collective self-citations but less so with citations by others

ObjectiveThis study investigated the associations between the number of authors and collective self-citations versus citations by others.Study design and settingWe analyzed 88,594 health science articles published in 2015 and citations they received until 2020. The main variables were the number of authors, the number of citations by co-authors (collective self-citations), and the number of citations by others.ResultsThe number of authors correlated more strongly with the number of citations by co-authors than with citations by others (Spearman r 0.31 vs. 0.23; mutually adjusted r 0.26 vs. 0.12). The percentage of self-citations among all citations was 10.6% for single-authored articles, and increased gradually with the number of authors to 34.8% for ≥ 50 authors. Collective self-citations increased the proportion of articles reaching or exceeding 30 total citations by 0.7% for single-authored articles, but by 11.6% for articles written by ≥ 50 authors.ConclusionsIf citations by others reflect scientific utility, then another mechanism must explain the excess of collective self-citations observed for multi-authored articles. The results support the hypothesis that the authors’ own motivations explain this excess. The evaluation of scientific utility should also be based on citations by others, excluding collective self-citations.

The Evolving Trends in the Impact Factor of Plastic Surgery Journals: A 22-Year Analysis.

The journal impact factor (IF) is one of the most widely adopted metrics to assess journal value. We aimed to investigate the trends in the IF and ranking of plastic surgery journals (PSJs) over a 22-year period. The Journal Citation Report 2018 was used to identify all journals within the field of plastic surgery from 1997 to 2018. We analyzed the IF of PSJs and that of the category surgery. A total of 34 PSJs were identified. The mean IF increased from 0.584 (median, 0.533) in 1997 to 1.58 (median, 1.399) in 2018 (P < 0.0001). Over the same time, the median IF of the journals in the category surgery increased from 0.914 to 1.883. The mean journal IF percentile of PSJs within surgery remained fairly stable (P = 0.999). A strong positive correlation was identified between the IF of PSJs and both the 5-year IF (r = 0.943, P < 0.0001) and the immediacy index (r = 0.736, P < 0.0001). The percentage of self-citations across the study period was fairly stable at a mean of 19.2%. A weak positive correlation was found between the IF and the percentage of self-citations (r = 0.171, P < 0.0001). The mean journal IF in PSJs has been trending upward over the last 22 years. Ranking of PSJs IF within the category surgery has remained unchanged. The self-citation rate has been fairly stable and correlated weakly with the IF. A strong positive correlation exists between the IF and both the immediacy index and the 5-year IF.

Self-citations, a trend prevalent across subject disciplines at the global level: an overview

PurposeThe present study aims to determine the prevailing trend of self-citations across 27 major subject disciplines at global level. The study also examines the aspects like percentage of self-citations in each individual subject discipline and the average number of self-citations per publication across different subject disciplines. The study also investigates self-citation percentage of research articles published from the 20 leading research countries of the world and across the continents.Design/methodology/approachThe study is supported by empirical findings undertaken on secondary data retrieved from SCImago Journal and Country Ranking, which is entirely based on the SCOPUS data source (SCImago, 2014).FindingsIn all, 76,634,557 citations were received by as many as 14,946,975 research articles published from 2008-2012 at an average of 5.12 citations per article. Of the total citations received, 26,404,609 (34.45 per cent) were self-citations, which means that of the total citations received by each research article, 1.76 are self-citations. Compared to subject disciplines falling under social and humanistic sciences, pure and applied sciences have shown a greater trend of self-citation. On average, 4.18 self-citations were observed in each research article published in multidisciplinary subject disciplines. Of the total citations received by research articles published in the discipline of Psychology, 43.69 per cent are self-citations, the highest among all the subject disciplines under study. Of the total self-citations received by all the subject disciplines under study, 18.43 per cent were received alone in medicine, highest among all, whereas Social and Humanistic sciences received less than 1.00 per cent self-citations, the lowest among all the subject disciplines.Originality/valueThis study is original and first of its kind covering each individual subject discipline having global scope.

Impact of Self-Citations on Impact Factor: A Study Across Disciplines, Countries and Continents

Purpose. The present study is an attempt to find out the impact of self-citations on Impact Factor (IF) across disciplines. The study examines the number of research articles published across 27 major subject fields covered by SCImago, encompassing as many as 310 sub-disciplines. The study evaluates aspects like percentage of self-citations across each discipline, leading self-citing countries and continents, and the impact of self-citation on their IF. Scope. The study is global in nature, as it evaluates the trend of self-citation and its impact on IF of all the major subject disciplines of the world, along with countries and continents. IF has been calculated for the year 2012 by analyzing the articles published during the years 2010 and 2011. Methodology/Approach. The study is empirical in nature; as such, statistical and mathematical tools and techniques have been employed to work out the distribution across disciplines. The evaluation has been purely under-taken on the secondary data, retrieved from SCImago Journal and Country Ranking. Findings. Self-citations play a very significant part in inflating IF. All the subject fields under study are influenced by the practice of self-citation, ranging from 33.14% to 52.38%. Compared to the social sciences and the humanities, subject fields falling under the purview of pure and applied sciences have a higher number of self-citations, but a far lesser percentage than the social sciences and humanities. Upon excluding self-citations, a substantial amount of change was observed in the IF of subject fields under study, as 18 (66.66%) out of 27 subjects fields faced shuffle in their rankings. Variation in rankings based on IF with and without self-citation was observed at subject level, country level, and continental level.

Potentially coercive self-citation by peer reviewers: A cross-sectional study

ObjectivePeer reviewers sometimes request that authors cite their work, either appropriately or via coercive self-citation to highlight the reviewers' work. The objective of this study was to determine in peer reviews submitted to one biomedical journal (1) the extent of peer reviewer self-citation; (2) the proportion of reviews recommending revision or acceptance versus rejection that included reviewer self-citations; and (3) the proportion of reviewer self-citations versus citations to others that included a rationale. MethodsPeer reviews for manuscripts submitted in 2012 to the Journal of Psychosomatic Research were evaluated. Data extraction was performed independently by two investigators. ResultsThere were 616 peer reviews (526 reviewers; 276 manuscripts), of which 444 recommended revision or acceptance and 172 rejection. Of 428 total citations, there were 122 peer reviewer self-citations (29%) and 306 citations to others' work (71%). Self-citations were more common in reviews recommending revision or acceptance (105 of 316 citations; 33%) versus rejection (17/112; 15%; p<0.001). The percentage of self-citations with no rationale (26 of 122; 21%) was higher than for citations to others' work (15 of 306; 5%; p<0.001). ConclusionsSelf-citation in peer reviews is common and may reflect a combination of appropriate citation to research that should be cited in published articles and inappropriate citation intended to highlight the work of the peer reviewer. Providing instructions to peer reviewers about self-citation and asking them to indicate when and why they have self-cited may help to limit self-citation to appropriate, constructive recommendations.

Measuring the Surgical Academic Output of an Institution: The “Institutional” H-Index

The Hirsch index is a novel index that combines the number of publications and citations in measuring the research output of researchers. We hypothesized that the h-index can be used to measure the academic success of an institution in a subject area (surgery) and compared this measure to previously published measures of ranking institutions. We identified the top 10 research medical schools as designated by the United States News and World Report 2010. The h-index for an institution was obtained in 3-year periods for articles published in surgery. Independent rankings from the NIH and other web sites were then used to compare with our newly generated rankings. The median h-index for institutions was 52.5 (46-54) for 2000-2002, 50 (44-52) for 2003-2005, 35.5 (33-40) for 2006-2008, and 15.5 (13-16) for 2009-2011. The percentage of self citations was the highest in publications from Harvard University (22.2%) and the lowest from Columbia University (10%) in the years 2009-11. Our ranking closely mirrored the United States News and World Report, and Harvard Medical School remains the top ranking in the field of surgery, although NIH funding-based ranking may suggest otherwise. The institutional h-index appears to be a viable indicator for the measure of academic success of institutions in a subject area. Despite limitations, it yields objective data regarding the citations and number of articles published by an institution in a subject area and could be used to measure performance.

A Good Start

A few weeks ago, Deutsches Arzteblatt was given its first impact factor, with a value of 1.099. This sets Deutsches Arzteblatt squarely in the middle of the 133 general medical journals from around the world that Thomson Reuters, the publisher of the impact factor, includes in its category “Medicine, General and Internal.” A good start! Strictly speaking, the impact factor was not assigned to Deutsches Arzteblatt itself, but to the online journal that you are now reading, Deutsches Arzteblatt International, which includes all of the articles published in German under the heading Medizin (“Medicine”) in full English translation. Thus, all of the medical-scientific articles that have undergone our review process are published in English in Deutsches Arzteblatt International. The online sister publication was founded by Deutsches Arzteblatt in 2008 so that our articles could be indexed in the major medical databases, such as Medline as well as, indeed, Web of Science and Journal Citation Report. This was by no means an end in itself: the purpose was, rather, to enable us to present our readers with scientific articles of even higher quality. It has become difficult for any journal that is not represented in the major databases to acquire good authors, researchers today being subject to the constant pressure of evaluations which, in turn, employ the impact factor as their main instrument. There is some debate at present about this type of evaluation, and about the impact factor itself (1– 6). Nonetheless, no researcher and no editor of a scientific journal can afford to ignore the impact factor, as this ostensibly simple, and therefore alluring, statistic has already become immensely popular among the research bureaucracy. We are glad, therefore, to be able to offer our authors not just the huge medical readership of Deutsches Arzteblatt with its weekly circulation of 400 000 copies (which surely constitutes its true “impact”), but also bilinguality, visibility in Medline, and now an impact factor as well. The new journal, Deutsches Arzteblatt Internationl, is unusual for its bilinguality. Accordingly, the impact factor it has just received is unusual as well. As with all newly founded journals, the impact factor for the first year is a one-year impact factor, i.e., it is based on citations drawn from one publication year (2008, in this case), rather than two. Furthermore, problems arising from bilinguality unfortunately led to the lack of consideration of at least 69.6% (7) of all citations of scientific articles from Deutsches Arzteblatt’s section “Medicine” in other medical journals. This, along with the large number of letters to the editor that we are happy to publish, far more than in other journals, led to a non-representative distortion of the percentage of self-citations. In order to keep such artifacts from arising in the future, we kindly ask all authors of scientific papers to cite scientific articles from Deutsches Arzteblatt exclusively in their English version.

Estudio bibliométrico de la producción científica de la Revista de Nutrição através de la Red SciELO (2001 a 2007)

Objetivo Evaluar, mediante el análisis bibliométrico, la actividad científica, la producción y el consumo de información de la Revista de Nutrição, como publicación científica del área de las ciencias de la salud, en el periodo 2001 a 2007. Metodos Estudio descriptivo trasversal de la actividad y la producción de información científica publicada en la Revista de Nutrição, a través de la Red Scientific Electronic Library Online, en el periodo estudiado. Resultuado Se publicaron un total de 368 artículos. El número de artículos originales fue de 241 (65,49%), con un índice de productividad del 2,38. Se identificaron 85 instituciones con trabajos publicados en la revista. El idioma predominante es el portugués, con 349 artículos (94,84%). Se contabilizaron 1574 palabras clave, de las cuales 1135 (72,11%) correspondían a los términos DeCS o MeSH;102 artículos (27,72%) presentaban todas las palabras clave equivalentes a Descriptores. El estudio de las palabras clave muestra una orientación claramente comunitaria. La obsolescencia de las referencias citadas en Revista de Nutrição, medida por la Mediana es de 11 y el Índice de Price es del 11,69%. El porcentaje de autocitas es de 2,08%. Conclusione En términos generales la Revista de Nutrição, publicación de ámbito internacional, se mantiene dentro de los indicadores bibliométricos de las revistas de las ciencias de la salud publicadas en países iberoamericanos. Presenta un porcentaje excelente de equivalencia entre las Palabras Clave y los Descriptores de Ciencias de la Salud. La obsolescencia de sus referencias es algo elevada, situación que fue corregida en los años 2006 y 2007, los últimos del estudio.

Self-citations at the meso and individual levels: effects of different calculation methods

This paper focuses on the study of self-citations at the meso and micro (individual) levels, on the basis of an analysis of the production (1994–2004) of individual researchers working at the Spanish CSIC in the areas of Biology and Biomedicine and Material Sciences. Two different types of self-citations are described: author self-citations (citations received from the author him/herself) and co-author self-citations (citations received from the researchers’ co-authors but without his/her participation). Self-citations do not play a decisive role in the high citation scores of documents either at the individual or at the meso level, which are mainly due to external citations. At micro-level, the percentage of self-citations does not change by professional rank or age, but differences in the relative weight of author and co-author self-citations have been found. The percentage of co-author self-citations tends to decrease with age and professional rank while the percentage of author self-citations shows the opposite trend. Suppressing author self-citations from citation counts to prevent overblown self-citation practices may result in a higher reduction of citation numbers of old scientists and, particularly, of those in the highest categories. Author and co-author self-citations provide valuable information on the scientific communication process, but external citations are the most relevant for evaluative purposes. As a final recommendation, studies considering self-citations at the individual level should make clear whether author or total self-citations are used as these can affect researchers differently.

Citation analysis in research on differential item functioning

This paper offers a first approach to the study of citing behaviour in the literature on differential item functioning (DIF) and provides new information about the main characteristics that define that behaviour. With a focus on articles listed in the Web of Science for the period 1975–2000, the present research considers the number of self-citations included in each paper with respect to other bibliometric indicators such as year of publication, the number of signatories to a paper, author’s country of origin and the journal in which it was published. In general terms it can be concluded that in studies of DIF the mean percentage of self-citations is around 11%, this figure remaining stable over time; there is a positive correlation between the number of signatories to an article and the number of self-citations. This paper has offered a first approach to the study of citing behaviour in the literature on DIF.

How much the shared ocean or lake basins connect the researchers in neighbouring countries?

This paper evaluates the importance of jointly conducted research versus national, when neighbouring countries are trying to study a topic of their mutual interest. The chosen topic was the shared ocean or lake basin. The number of non-mutual and mutual articles in the period 1999–2008 for seven pairs of neighbouring countries was analysed by extracting published articles and citations from the Web of Science database. It was found that mutual articles have generally better visibility than the non-mutual articles, valid even for large and developed countries. Also, the percentage of self-citations in the mutual articles is much lower than in the non-mutual ones. However, the citations of the non-mutual articles are influenced by the development of the country or, in some cases, by the development of the countries in which researchers from a certain country are presently working (this applies strongly to the Eastern Europe countries).

In this issue

In this issue

Análisis de citas y factor de impacto nacional e internacional de Farmacia Hospitalaria (2001-2005)

The objective of this study is to analyse the citation patterns and impact and immediacy indicators of the Farmacia Hospitalaria journal during the period 2001-2005. An analysis of citations chosen from 101 Spanish health science journals was carried out in order to determine the citing and cited journals and the national and international impact and immediacy indicators. A similar methodology used by Thomson ISI in Science Citation Index (SCI) and Journal Citation Reports (JRC) was applied. Farmacia Hospitalaria made 1,370 citations to 316 different journals. The percentage of self-citations was 9%. The national impact factor increased from 0.178 points in 2001 to 0.663 points in 2005 while the international impact factor increased from 0.178 to 0.806 for the same period. The analysis of citation patterns demonstrates the multidisciplinary nature of Farmacia Hospitalaria and a significant growth in the impact indicators over recent years. These indicators are higher than those of some other pharmacy journals included in Journal Citation Reports. Self-citation was not excessive and was similar to that of other journals.