Citation advantage of open access articles

Open access (OA) to the research literature has the potential to accelerate recognition and dissemination of research findings, but its actual effects are controversial. This was a longitudinal bibliometric analysis of a cohort of OA and non-OA articles published between June 8, 2004, and December 20, 2004, in the same journal (PNAS: Proceedings of the National Academy of Sciences). Article characteristics were extracted, and citation data were compared between the two groups at three different points in time: at “quasi-baseline” (December 2004, 0–6 mo after publication), in April 2005 (4–10 mo after publication), and in October 2005 (10–16 mo after publication). Potentially confounding variables, including number of authors, authors' lifetime publication count and impact, submission track, country of corresponding author, funding organization, and discipline, were adjusted for in logistic and linear multiple regression models. A total of 1,492 original research articles were analyzed: 212 (14.2% of all articles) were OA articles paid by the author, and 1,280 (85.8%) were non-OA articles. In April 2005 (mean 206 d after publication), 627 (49.0%) of the non-OA articles versus 78 (36.8%) of the OA articles were not cited (relative risk = 1.3 [95% Confidence Interval: 1.1–1.6]; p = 0.001). 6 mo later (mean 288 d after publication), non-OA articles were still more likely to be uncited (non-OA: 172 [13.6%], OA: 11 [5.2%]; relative risk = 2.6 [1.4–4.7]; p < 0.001). The average number of citations of OA articles was higher compared to non-OA articles (April 2005: 1.5 [SD = 2.5] versus 1.2 [SD = 2.0]; Z = 3.123; p = 0.002; October 2005: 6.4 [SD = 10.4] versus 4.5 [SD = 4.9]; Z = 4.058; p < 0.001). In a logistic regression model, controlling for potential confounders, OA articles compared to non-OA articles remained twice as likely to be cited (odds ratio = 2.1 [1.5–2.9]) in the first 4–10 mo after publication (April 2005), with the odds ratio increasing to 2.9 (1.5–5.5) 10–16 mo after publication (October 2005). Articles published as an immediate OA article on the journal site have higher impact than self-archived or otherwise openly accessible OA articles. We found strong evidence that, even in a journal that is widely available in research libraries, OA articles are more immediately recognized and cited by peers than non-OA articles published in the same journal. OA is likely to benefit science by accelerating dissemination and uptake of research findings.     

Citation Classics in Systematic Reviews and Meta-Analyses: Who Wrote the Top 100 Most Cited Articles?

Background

Systematic reviews of the literature occupy the highest position in currently proposed hierarchies of evidence. The aims of this study were to assess whether citation classics exist in published systematic review and meta-analysis (SRM), examine the characteristics of the most frequently cited SRM articles, and evaluate the contribution of different world regions.

Methods

The 100 most cited SRM were identified in October 2012 using the Science Citation Index database of the Institute for Scientific Information. Data were extracted by one author. Spearman’s correlation was used to assess the association between years since publication, numbers of authors, article length, journal impact factor, and average citations per year.

Results

Among the 100 citation classics, published between 1977 and 2008, the most cited article received 7308 citations and the least-cited 675 citations. The average citations per year ranged from 27.8 to 401.6. First authors from the USA produced the highest number of citation classics (n=46), followed by the UK (n=28) and Canada (n=15). The 100 articles were published in 42 journals led by the Journal of the American Medical Association (n=18), followed by the British Medical Journal (n=14) and The Lancet (n=13). There was a statistically significant positive correlation between number of authors (Spearman’s rho=0.320, p=0.001), journal impact factor (rho=0.240, p=0.016) and average citations per year. There was a statistically significant negative correlation between average citations per year and year since publication (rho = -0.636, p=0.0001). The most cited papers identified seminal contributions and originators of landmark methodological aspects of SRM and reflect major advances in the management of and predisposing factors for chronic diseases.

Conclusions

Since the late 1970s, the USA, UK, and Canada have taken leadership in the production of citation classic papers. No first author from low or middle-income countries (LMIC) led one of the most cited 100 SRM.     

Content Factor: A Measure of a Journal's Contribution to Knowledge

Impact Factor, the pre-eminent performance metric for medical journals, has been criticized for failing to capture the true impact of articles; for favoring methodology papers; for being unduly influenced by statistical outliers; and for examining a period of time too short to capture an article's long-term importance. Also, in the era of search engines, where readers need not skim through journals to find information, Impact Factor's emphasis on citation efficiency may be misplaced. A better metric would consider the total number of citations to all papers published by the journal (not just the recent ones), and would not be decremented by the total number of papers published. We propose a metric embodying these principles, "Content Factor", and examine its performance among leading medical and orthopaedic surgery journals. To remedy Impact Factor's emphasis on recent citations, Content Factor considers the total number of citations, regardless of the year in which the cited paper was published. To correct for Impact Factor's emphasis on efficiency, no denominator is employed. Content Factor is thus the total number of citations in a given year to all of the papers previously published in the journal. We found that Content Factor and Impact Factor are poorly correlated. We further surveyed 75 experienced orthopaedic authors and measured their perceptions of the "importance" of various orthopaedic surgery journals. The correlation between the importance score and the Impact Factor was only 0.08; the correlation between the importance score and Content Factor was 0.56. Accordingly, Content Factor better reflects a journal's "importance". In sum, while Content Factor cannot be defended as the lone metric of merit, to the extent that performance data informs journal evaluations, Content Factor- an easily obtained and intuitively appealing metric of the journal's knowledge contribution, not subject to gaming- can be a useful adjunct.     

Impact analysis of a regional scientific journal (1980-2000): supporting promising local researchers pays the greatest dividends

During the past 28 years, the journal "Collegium Antropologicum" has continuously served as one of the main disseminators of anthropological scientific production in Central and Eastern Europe. The journal was committed to its role of a multidisciplinary platform for presenting wide range of research topics relevant to anthropology, from investigations within social and cultural anthropology and archaeology to those covering contemporary population genetics, human evolution and biomedical issues. Two key strategies aimed at sustaining and increasing the impact of this journal were oriented towards: (i) identification of promising local groups of researchers who were at disadvantage by many aspects (e.g. educational curricula, financial supports, language barriers etc.) when trying to publish their research internationally, and (ii) invitation and encouragement of already established international scientists to make contributions for "Collegium Antropologicum". From 1980-2000, 89 articles (or 6.3% of all published papers during that period) were cited 6 or more times, contributing disproportionately to journal's impact (nearly a third of all citations received). In an attempt to identify such papers more readily among the submissions to the journal in the future, we analyzed research topics and affiliations of the authors among the 89 papers receiving most citations in comparison to all papers published. Among the papers most frequently cited, we found greater-than-expected prevalence of Croatian researchers (especially when publishing in collaboration with international scientists) and studies of special populations. Several papers received more than 25 citations or had overall citation intensity greater than 2 per year. This implies that an interesting article from a local group of researchers can still resonate with international audience although published in a regional journal. Present analysis supports current editorial strategy that with a help of the international consulting editorial board continuously improves international recognition of this journal. The results imply that a balanced encouragement to promising local groups of researchers and to contributions of already established international scientists is a strategy superior to others in maintaining and increasing the impact of this regional journal.     

Incorrect Citations Give Unfair Credit to Review Authors in Ecology Journals

The number of citations that papers receive has become significant in measuring researchers'' scientific productivity, and such measurements are important when one seeks career opportunities and research funding. Skewed citation practices can thus have profound effects on academic careers. We investigated (i) how frequently authors misinterpret original information and (ii) how frequently authors inappropriately cite reviews instead of the articles upon which the reviews are based. To reach this aim, we carried a survey of ecology journals indexed in the Web of Science and assessed the appropriateness of citations of review papers. Reviews were significantly more often cited than regular articles. In addition, 22% of citations were inaccurate, and another 15% unfairly gave credit to the review authors for other scientists'' ideas. These practices should be stopped, mainly through more open discussion among mentors, researchers and students.     

Reference bias in reports of drug trials.

Articles published before 1985 describing double blind trials of two or more non-steroidal anti-inflammatory drugs in rheumatoid arthritis were examined to see whether there was any bias in the references they cited. Althogether 244 articles meeting the criteria were found through a Medline search and through examining the reference lists of the articles retrieved. The drugs compared in the studies were classified as new or as control drugs and the outcome of the trial as positive or not positive. The reference lists of all papers with references to other trials on the new drug were then examined for reference bias. Positive bias was judged to have occurred if the reference list contained a higher proportion of references with a positive outcome for that drug than among all the articles assumed to have been available to the authors (those published more than two years earlier than the index article). Altogether 133 of the 244 articles were excluded for various reasons--for example, 44 because of multiple publication and 19 because they had no references. Among the 111 articles analysed bias was not possible in the references of 35 (because all the references gave the same outcome); 10 had a neutral selection of references, 22 a negative selection, and 44 a positive selection--a significant positive bias. This bias was not caused by better scientific standing of the cited articles over the uncited ones. Thus retrieving literature by scanning reference lists may produce a biased sample of articles, and reference bias may also render the conclusions of an article less reliable.     

High-Ranked Social Science Journal Articles Can Be Identified from Early Citation Information

Do citations accumulate too slowly in the social sciences to be used to assess the quality of recent articles? I investigate whether this is the case using citation data for all articles in economics and political science published in 2006 and indexed in the Web of Science. I find that citations in the first two years after publication explain more than half of the variation in cumulative citations received over a longer period. Journal impact factors improve the correlation between the predicted and actual future ranks of journal articles when using citation data from 2006 alone but the effect declines sharply thereafter. Finally, more than half of the papers in the top 20% in 2012 were already in the top 20% in the year of publication (2006).     

The influence of “Homage to Santa Rosalia” on aquatic ecology: a scientometric approach

In 1959, G.E. Hutchinson provided a general explanation for the diversity of species in his paper “Homage to Santa Rosalia or why are there so many kinds of animals?” To assess the contribution of the ideas Hutchinson introduced in “The Homage” to aquatic ecology research, we performed a bibliometric evaluation of all the articles that cited this paper between 1960 and 2009. The articles were retrieved using the database from Thomson Reuters (ISI Web of Knowledge) in March 2009. For each paper, we first identified the studied environment (terrestrial, marine or freshwater) and whether the study was theoretical or empirical. For marine and freshwater studies, we recorded the journal where the article was published, the year of publication, the number of citations, the taxonomic group (e.g. fish, phytoplankton, zooplankton, macroinvertebrates or macrophytes), the habitat (e.g. wetlands, lakes, rivers, streams or ocean) and the main ideas addressed. A total of 1345 articles cited “The Homage”, and the number of citations increased significantly with time. Most of the articles that cited “The Homage” described research carried out in a terrestrial environment or were theoretical, and a lesser number of citations came from freshwater and marine papers, which used mainly fish and invertebrates as model organisms. In the aquatic sciences, most of the papers discussed the influences of competition and energy (productivity) on diversity. Our results indicate that “The Homage” can still be considered a “citation classic” and a breakthrough contribution, and that it is still having a great impact on different fields of ecology, including limnology and marine ecology.     

Reasons for Journal Impact Factor Changes: Influence of Changing Source Items

Both the concept and the application of the impact factor (IF) have been subject to widespread critique, including concerns over its potential manipulation. This study provides a systematic analysis of significant journal Impact Factor changes, based on the relative contribution of either one or both variables of the IF equation (i.e. citations / articles as the numerator / denominator of the quotient). A cohort of JCR-listed journals which faced the most dramatic absolute IF changes between 2013 and 2014 (ΔIF ≥ 3.0, n = 49) was analyzed for the causes resulting in IF changes that theses journals have experienced in the last five years. Along with the variation by number of articles and citations, this analysis includes the relative change of both variables compared to each other and offers a classification of `valid`and `invalid`scenarios of IF variation in terms of the intended goal of the IF to measure journal quality. The sample cohort features a considerable incidence of IF increases (18%) which are qualified as `invalid`according to this classification because the IF increase is merely based on a favorably changing number of articles (denominator). The results of this analysis point out the potentially delusive effect of IF increases gained through effective shrinkage of publication output. Therefore, careful consideration of the details of the IF equation and possible implementation of control mechanisms versus the volatile factor of number of articles may help to improve the expressiveness of this metric.     

Quantifying shifts in topic popularity over 44 years of Austral Ecology

The Ecological Society of Australia was founded in 1959, and the society’s journal was first published in 1976. To examine how research published in the society’s journal has changed over this time, we used text mining to quantify themes and trends in the body of work published by the Australian Journal of Ecology and Austral Ecology from 1976 to 2019. We used topic models to identify 30 ‘topics’ within 2778 full‐text articles in 246 issues of the journal, followed by mixed modelling to identify topics with above‐average or below‐average popularity in terms of the number of publications or citations that they contain. We found high inter‐decadal turnover in research topics, with an early emphasis on highly specific ecosystems or processes giving way to a modern emphasis on community, spatial and fire ecology, invasive species and statistical modelling. Despite an early focus on Australian research, papers discussing South American ecosystems are now among the fastest‐growing and most frequently cited topics in the journal. Topics that were growing fastest in publication rates were not always the same as those with high citation rates. Our results provide a systematic breakdown of the topics that Austral Ecology authors and editors have chosen to research, publish and cite through time, providing a valuable window into the historical and emerging foci of the journal.     

Bibliometric analysis of global scientific research on carbapenem resistance (1986–2015)

Background

Antimicrobial resistance is a global public health challenge and carbapenem resistance, in particular, is considered an urgent global health threat. This study was carried out to give a bibliometric overview of literature on carbapenem resistance. In specific, number of publications, top productive countries and institutes, highly cited articles, citation analysis, co-authorships, international collaboration, top active authors, and journals publishing articles on carbapenem resistance were analyzed and discussed.

Methods

Specific keywords pertaining to carbapenem resistance were used in Scopus database. Quantitative and qualitative analysis of retrieved data were presented using appropriate bibliometric indicators and visualization maps.

Results

A total of 2617 journal articles were retrieved. The average number of citations per article was of 21.47. The growth of publications showed a dramatic increase from 2008 to 2015. Approximately 9 % of retrieved articles on carbapenem resistance were published in Antimicrobial Agents and Chemotherapy journal. Retrieved articles were published by 102 different countries. The United States of America (USA) contributed most with 437 (16.70 %) articles followed by China with 257 (9.82 %) articles. When productivity was stratified by population size, Greece ranked first followed by France. Greece also ranked first when data were stratified by gross domestic product (GDP). Asian countries have lesser international collaboration compared with other countries in the top ten list. Five of top ten productive institutes were Europeans (France, the UK, Greece, Italy, and Switzerland) and two were Asians (China and South Korea). Other active institutes included an Israeli and a Brazilian institute. Four of the top ten cited articles were published in Antimicrobial Agents and Chemotherapy journal and two were published in The Lancet Infectious Diseases.

Conclusion

There was a dramatic increase in number of publications on carbapenem resistance in the past few years. These publications were produced from different world regions including Asia, Europe, Middle East, and Latin America. International collaboration needs to be encouraged particularly for researchers in Asia. Molecular biology and epidemiology dominated the theme of the top ten cited articles on carbapenem resistance. This bibliometric study will hopefully help health policy makers in planning future research and allocating funds pertaining to carbapenem resistance.

     

Academic Impact of Qualitative Studies in Healthcare: Bibliometric Analysis

Context

Although qualitative studies are becoming more appreciated in healthcare, the number of publications of quality studies remains low. Little is known about the frequency and characteristics of citation in qualitative studies.

Objective

To compare the academic impact of qualitative studies to that of two quantitative studies: systematic reviews and randomized controlled trials.

Methods

Publications in BMJ between 1997 and 2006 (BMJ’s median impact factor was 7.04 during this period) employing qualitative methods were matched to two quantitative studies appearing the same year using PubMed. Using Web of Science, citations within a 24-month publication period were determined. Additionally, three hypotheses were examined: qualitative studies are 1) infrequently cited in original articles or reviews; 2) rarely cited by authors in non-English-speaking countries; and 3) more frequently cited in non-medical disciplines (e.g., psychology or sociology).

Results

A total of 121 qualitative studies, 270 systematic reviews, and 515 randomised controlled trials were retrieved. Qualitative studies were cited a total of 1,089 times, with a median of 7.00 times (range, 0–34) for each study. Matched systematic reviews and randomized controlled trials were cited 2,411times and 1,600 times, respectively. With respect to citing documents, original articles and reviews exceeded 60% for each study design. Relative to quantitative studies, qualitative studies were cited more often by authors in English-speaking countries. With respect to subject area, medical disciplines were more frequently cited than non-medical disciplines for all three study designs (>80%).

Conclusion

The median number of citations for qualitative studies was almost the same as the median of BMJ’s impact factor during the survey period. For a suitable evaluation of qualitative studies in healthcare, it will be necessary to develop a reporting framework and include explicit discussions of clinical implications when reporting findings. Coordination between researchers and editors will be needed to achieve this goal.     

Universality of Citation Distributions for Academic Institutions and Journals

Citations measure the importance of a publication, and may serve as a proxy for its popularity and quality of its contents. Here we study the distributions of citations to publications from individual academic institutions for a single year. The average number of citations have large variations between different institutions across the world, but the probability distributions of citations for individual institutions can be rescaled to a common form by scaling the citations by the average number of citations for that institution. We find this feature seems to be universal for a broad selection of institutions irrespective of the average number of citations per article. A similar analysis for citations to publications in a particular journal in a single year reveals similar results. We find high absolute inequality for both these sets, Gini coefficients being around 0.66 and 0.58 for institutions and journals respectively. We also find that the top 25% of the articles hold about 75% of the total citations for institutions and the top 29% of the articles hold about 71% of the total citations for journals.     

Editorial Bias in Crowd-Sourced Political Information

The Internet has dramatically expanded citizens’ access to and ability to engage with political information. On many websites, any user can contribute and edit “crowd-sourced” information about important political figures. One of the most prominent examples of crowd-sourced information on the Internet is Wikipedia, a free and open encyclopedia created and edited entirely by users, and one of the world’s most accessed websites. While previous studies of crowd-sourced information platforms have found them to be accurate, few have considered biases in what kinds of information are included. We report the results of four randomized field experiments that sought to explore what biases exist in the political articles of this collaborative website. By randomly assigning factually true but either positive or negative and cited or uncited information to the Wikipedia pages of U.S. senators, we uncover substantial evidence of an editorial bias toward positivity on Wikipedia: Negative facts are 36% more likely to be removed by Wikipedia editors than positive facts within 12 hours and 29% more likely within 3 days. Although citations substantially increase an edit’s survival time, the editorial bias toward positivity is not eliminated by inclusion of a citation. We replicate this study on the Wikipedia pages of deceased as well as recently retired but living senators and find no evidence of an editorial bias in either. Our results demonstrate that crowd-sourced information is subject to an editorial bias that favors the politically active.     

1997—2009年《生命科学研究》载文、作者、基金资助论文和影响因子统计分析

对<生命科学研究)1997-2009年的载文、作者、基金支持论文和影响因子情况进行了统计分析,得出该刊13年来发展的一些规律,为进一步提高该刊的学术水平和影响力提供依据.利用维普(VIP)资讯系统(中文科技期刊数据库),采用文献计量法,分析<生命科学研究>1997-2009年的载文量、作者合作度、合作率、以及地域分布、基金支持、影响因子等指标和内容.13年共检出886篇文献,作者3 544人次,合作度为4,合著率为94.92%.作者分布在全国29个省、自治区和直辖市,高等医药院校作者最多.占作者总数的84.76%.13年<生命科学研究>共发表各类基金资助论文734篇.影响因子和总被引频次逐年提升.该刊因其著者整体学术水平高,在生命科学研究领域有较大的影响.已成为我国生命科学研究领域具有普遍的指导意义、影响深远的重要学术性期刊和中文核心期刊.