Related Articles

Aim

To analyze the 2007 citation count of articles published by the Croatian Medical Journal in 2005-2006 based on data from the Web of Science, Scopus, and Google Scholar.

Methods

Web of Science and Scopus were searched for the articles published in 2005-2006. As all articles returned by Scopus were included in Web of Science, the latter list was the sample for further analysis. Total citation counts for each article on the list were retrieved from Web of Science, Scopus, and Google Scholar. The overlap and unique citations were compared and analyzed. Proportions were compared using χ2-test.

Results

Google Scholar returned the greatest proportion of articles with citations (45%), followed by Scopus (42%), and Web of Science (38%). Almost a half (49%) of articles had no citations and 11% had an equal number of identical citations in all 3 databases. The greatest overlap was found between Web of Science and Scopus (54%), followed by Scopus and Google Scholar (51%), and Web of Science and Google Scholar (44%). The greatest number of unique citations was found by Google Scholar (n = 86). The majority of these citations (64%) came from journals, followed by books and PhD theses. Approximately 55% of all citing documents were full-text resources in open access. The language of citing documents was mostly English, but as many as 25 citing documents (29%) were in Chinese.

Conclusion

Google Scholar shares a total of 42% citations returned by two others, more influential, bibliographic resources. The list of unique citations in Google Scholar is predominantly journal based, but these journals are mainly of local character. Citations received by internationally recognized medical journals are crucial for increasing the visibility of small medical journals but Google Scholar may serve as an alternative bibliometric tool for an orientational citation insight.

Objective

To examine the strength and consistency of the evidence on the relationship between depression and adherence to antihypertensive medications.

Methods

The MEDLINE, CINAHL, PsycINFO, Embase, SCOPUS, and ISI databases were searched from inception until December 11, 2009 for published studies of original research that assessed adherence to antihypertensive medications and used a standardized interview, validated questionnaire or International Classification of Diseases Ninth Revision (ICD-9) code to assess depression or symptoms of depression in patients with hypertension. Manual searching was conducted on 22 selected journals. Citations of included articles were tracked using Web of Science and Google Scholar. Two investigators independently extracted data from the selected articles and discrepancies were resolved by consensus.

Results

Eight studies were identified that included a total of 42,790 patients. 95% of these patients were from one study. Only 4 of the studies had the assessment of this relationship as a primary objective. Adherence rates varied from 29% to 91%. There were widely varying results within and across studies. All 8 studies reported at least one significant bivariate or multivariate negative relationship between depression and adherence to antihypertensive medications. Insignificant findings in bivariate or multivariate analyses were reported in 6 of 8 studies.

Conclusions

All studies reported statistically significant relationships between depression and poor adherence to antihypertensive medications, but definitive conclusions cannot be drawn because of substantial heterogeneity between studies with respect to the assessment of depression and adherence, as well as inconsistencies in results both within and between studies. Additional studies would help clarify this relationship.

Global maps of science can be used as a reference system to chart career trajectories, the location of emerging research frontiers, or the expertise profiles of institutes or nations. This paper details data preparation, analysis, and layout performed when designing and subsequently updating the UCSD map of science and classification system. The original classification and map use 7.2 million papers and their references from Elsevier’s Scopus (about 15,000 source titles, 2001–2005) and Thomson Reuters’ Web of Science (WoS) Science, Social Science, Arts & Humanities Citation Indexes (about 9,000 source titles, 2001–2004)–about 16,000 unique source titles. The updated map and classification adds six years (2005–2010) of WoS data and three years (2006–2008) from Scopus to the existing category structure–increasing the number of source titles to about 25,000. To our knowledge, this is the first time that a widely used map of science was updated. A comparison of the original 5-year and the new 10-year maps and classification system show (i) an increase in the total number of journals that can be mapped by 9,409 journals (social sciences had a 80% increase, humanities a 119% increase, medical (32%) and natural science (74%)), (ii) a simplification of the map by assigning all but five highly interdisciplinary journals to exactly one discipline, (iii) a more even distribution of journals over the 554 subdisciplines and 13 disciplines when calculating the coefficient of variation, and (iv) a better reflection of journal clusters when compared with paper-level citation data. When evaluating the map with a listing of desirable features for maps of science, the updated map is shown to have higher mapping accuracy, easier understandability as fewer journals are multiply classified, and higher usability for the generation of data overlays, among others.

Background

Author self-citation contributes to the overall citation count of an article and the impact factor of the journal in which it appears. Little is known, however, about the extent of self-citation in the general clinical medicine literature. The objective of this study was to determine the extent and temporal pattern of author self-citation and the article characteristics associated with author self-citation.

Methodology/Principal Findings

We performed a retrospective cohort study of articles published in three high impact general medical journals (JAMA, Lancet, and New England Journal of Medicine) between October 1, 1999 and March 31, 2000. We retrieved the number and percentage of author self-citations received by the article since publication, as of June 2008, from the Scopus citation database. Several article characteristics were extracted by two blinded, independent reviewers for each article in the cohort and analyzed in multivariable linear regression analyses. Since publication, author self-citations accounted for 6.5% (95% confidence interval 6.3–6.7%) of all citations received by the 328 articles in our sample. Self-citation peaked in 2002, declining annually thereafter. Studies with more authors, in cardiovascular medicine or infectious disease, and with smaller sample size were associated with more author self-citations and higher percentage of author self-citation (all p≤0.01).

Conclusions/Significance

Approximately 1 in 15 citations of articles in high-profile general medicine journals are author self-citations. Self-citation peaks within about 2 years of publication and disproportionately affects impact factor. Studies most vulnerable to this effect are those with more authors, small sample size, and in cardiovascular medicine or infectious disease.

Background

Citation counts are often regarded as a measure of the utilization and contribution of published articles. The objective of this study is to assess whether statistical reporting and statistical errors in the analysis of the primary outcome are associated with the number of citations received.

Methods

We evaluated all original research articles published in 1996 in four psychiatric journals. The statistical and reporting quality of each paper was assessed and the number of citations received up to 2005 was obtained from the Web of Science database. We then examined whether the number of citations was associated with the quality of the statistical analysis and reporting.

Results

A total of 448 research papers were included in the citation analysis. Unclear or inadequate reporting of the research question and primary outcome were not statistically significantly associated with the citation counts. After adjusting for journal, extended description of statistical procedures had a positive effect on the number of citations received. Inappropriate statistical analysis did not affect the number of citations received. Adequate reporting of the primary research question, statistical methods and primary findings were all associated with the journal visibility and prestige.

Conclusion

In this cohort of published research, measures of reporting quality and appropriate statistical analysis were not associated with the number of citations. The journal in which a study is published appears to be as important as the statistical reporting quality in ensuring dissemination of published medical science.

The large amount of information contained in bibliographic databases has recently boosted the use of citations, and other indicators based on citation numbers, as tools for the quantitative assessment of scientific research. Citations counts are often interpreted as proxies for the scientific influence of papers, journals, scholars, and institutions. However, a rigorous and scientifically grounded methodology for a correct use of citation counts is still missing. In particular, cross-disciplinary comparisons in terms of raw citation counts systematically favors scientific disciplines with higher citation and publication rates. Here we perform an exhaustive study of the citation patterns of millions of papers, and derive a simple transformation of citation counts able to suppress the disproportionate citation counts among scientific domains. We find that the transformation is well described by a power-law function, and that the parameter values of the transformation are typical features of each scientific discipline. Universal properties of citation patterns descend therefore from the fact that citation distributions for papers in a specific field are all part of the same family of univariate distributions.

Introduction

Mineral trioxide aggregate (MTA) has been suggested for root-end filling, vital pulp therapy, apical plug, perforations repair, and root canal filling. Since the introduction of MTA in 1993, many studies about this material have been published. The aim of this survey was to illustrate statistical information about published articles in PubMed-index journals vis-à-vis the various aspects of this biomaterial.

Material and Methods

A PubMed search was performed to retrieve the relative articles from 1993 to August 2012. The data of each article including publication year, journal name, number of authors, first author name, affiliations and study design were recorded. Citation of each article till 2009 was obtained from Scopus and Google scholar databases. Data were analyzed to determine the related scientometric indicators.

Results

In total, 1027 articles were found in PubMed-indexed journals which show considerable increase from 2 papers in 1993 to 139 in 2011. While ~62% of articles had no level of evidence, only ~5% could be classified as having the highest level of evidence (LOE1); however, the majority of LOE1 articles originated from Iran (~1%: n=10). Journal of Endodontics, as the top rank journal, published 31.7% of MTA related articles. The majority of articles were four-authored (19.6%). Most of the articles originated from USA (21.9%), Brazil (18.5%) and Iran (8.76%). The average number of citation for the top ten articles from Scopus was 231.

Conclusion

This data demonstrates that during the past two decades, research on this novel endodontic biomaterial had a rapid positive trend especially during the last 5 years. Further high-level evidence articles for the various clinical applications of MTA would result in superior clinical decision making and stronger scientific-based endodontic practice.

Background

Citation analysis as one of the most widely used methods of bibliometrics can be used for computing the various impact measures for scholars based on data from citation databases. Journal Citation Reports (JCR) from Thomson Reuters provides annual report in the form of impact factor (IF) for each journal.

Objectives

We aimed to evaluate the citation parameters of Hepatitis Monthly by JCR in 2010 and compare them with GS and Sc.

Materials and Methods

All articles of Hepat Mon published in 2009 and 2008 which had been cited in 2010 in three databases including WoS, Sc and GS gathered in a spreadsheet. The IFs were manually calculated.

Results

Among the 104 total published articles the accuracy rates of GS and Sc in recording the total number of articles was 96% and 87.5%. There was a difference between IFs among the three databases (0.793 in ISI [Institute for Scientific Information], 0.945 in Sc and 0.85 GS). The missing rate of citations in ISI was 4% totally. Original articles were the main cited types, whereas, guidelines and clinical challenges were the least ones.

Conclusions

None of the three databases succeed to record all articles published in the journal. Despite high sensitivity of GS comparing to Sc, it cannot be a reliable source for indexing since GS has lack of screening in the data collection and low specificity. Using an average of three IFs is suggested to find the correct IF. Editors should be more aware on the role of original articles in increasing IF and the potential efficacy of review articles in long term impact factor.

Introduction

The aim of this survey was to illustrate statistical information about endodontic research published in pubmed index journals from the different universities of Iran.

Materials and Methods

A PubMed search was performed to retrieve the endodontic publications of authors affiliated to different universities of Iran. Abstracts were reviewed and unrelated articles were omitted. Citation of each article was obtained from Scopus and Google scholar databases. Data were extracted and transferred to Microsoft Excel to determine the related scintometric indicators.

Results

A total of 307 papers were found according to the defined criteria which shows considerable increase from 2 papers in 1992 to 54 in 2011. The majority of the papers (48%) were related to in vitro studies; this number was 33% for in vivo surveys. Meta-analysis, systematic review and clinical trial constituted 10% of all publications. The average number of authors for the overall publications was 3.84; majority of articles (20%) were written by three authors. The average number of citation from Google Scholar (8.93) was higher than those from Scopus (4.74). Most of the endodontic articles originated from the Mashad University of Medical Sciences (16%).

Conclusion

Endodontic publication from different universities in Iran has considerably increased, showing that research is becoming more important.

Background

The contents of pharmaceutical industry sponsored supplements to medical journals are perceived to be less credible than the contents of their parent journals. It is unknown if their contents are cited as often. The objective of this study was to quantify the citability of original research and reviews contained in supplements and compare it with that for the parent journal.

Methodology/Principal Findings

This was a cohort study of 446 articles published in the Journal of Clinical Psychiatry (JCP) and its supplements for calendar years 2000 and 2005. The total citation counts for each article up to October 5, 2009 were retrieved from the ISI Web of Science database. The main outcome measure was the number of citations received by an article since publication. Regular journal articles included 114 from calendar year 2000 and 190 from 2005. Articles from supplements included 90 from 2000 and 52 from 2005. The median citation counts for the 3 years post-publication were 10 (interquartile range [IQR], 4–20), 14 (IQR, 8–20), 13.5 (IQR, 8–23), and 13.5 (IQR, 8–20), for the 2000 parent journal, 2000 supplements, 2005 parent journal, and 2005 supplements, respectively. Citation counts were higher for the articles in the supplements than the parent journal for the cohorts from 2000 (p = .02), and no different for the year 2005 cohorts (p = .88). The 2005 parent journal cohort had higher citation counts than the 2000 cohort (p = .007), in contrast to the supplements where citation counts remained the same (p = .94).

Conclusions/Significance

Articles published in JCP supplements are robustly cited and thus can be influential in guiding clinical and research practice, as well as shaping critical thinking. Because they are printed under the sponsorship of commercial interests, they may be perceived as less than objective. A reasonable step to help improve this perception would be to ensure that supplements are peer-reviewed in the same way as regular articles in the parent journal.

Introduction

The objective of this study was to identify and characterize the most highly cited clinical research articles published on sepsis.

Methods

A comprehensive list of citation classics in sepsis was generated by searching the database of Web of Science-Expanded (1970 to present) using keywords 'sepsis' or 'septic shock'. The top 50 cited clinical research papers were retrieved by reading the abstract or full text if needed. Each eligible article was reviewed for basic information, including country of origin, article type, journals, authors, and funding sources.

Results

A total of 2,151 articles were cited more than 100 times; the 50 top-cited clinical articles were published between 1974 and 2008. The number of citations ranged from 372 to 2,932, with a mean of 678 citations per article. These citation classics came from nine countries, of which 26 articles came from the United States. Rush University and the University of Pittsburgh lead the list of classics with six papers each. The 50 top-cited articles were published in 17 journals, with the New England Journal of Medicine and Journal of the American Medical Association topping the list. The top 50 articles consisted of 21 clinical trials and 29 observational studies.

Conclusions

Our bibliometric analysis provides a historical perspective on the progress of clinical research on sepsis. Articles originating from the United States and published in high-impact journals are most likely to be cited in the field of sepsis research.

CiTO, the Citation Typing Ontology, is an ontology for describing the nature of reference citations in scientific research articles and other scholarly works, both to other such publications and also to Web information resources, and for publishing these descriptions on the Semantic Web. Citation are described in terms of the factual and rhetorical relationships between citing publication and cited publication, the in-text and global citation frequencies of each cited work, and the nature of the cited work itself, including its publication and peer review status. This paper describes CiTO and illustrates its usefulness both for the annotation of bibliographic reference lists and for the visualization of citation networks. The latest version of CiTO, which this paper describes, is CiTO Version 1.6, published on 19 March 2010. CiTO is written in the Web Ontology Language OWL, uses the namespace http://purl.org/net/cito/, and is available from http://purl.org/net/cito/. This site uses content negotiation to deliver to the user an OWLDoc Web version of the ontology if accessed via a Web browser, or the OWL ontology itself if accessed from an ontology management tool such as Protégé 4 (http://protege.stanford.edu/). Collaborative work is currently under way to harmonize CiTO with other ontologies describing bibliographies and the rhetorical structure of scientific discourse.

Many scientists now manage the bulk of their bibliographic information electronically, thereby organizing their publications and citation material from digital libraries. However, a library has been described as “thought in cold storage,” and unfortunately many digital libraries can be cold, impersonal, isolated, and inaccessible places. In this Review, we discuss the current chilly state of digital libraries for the computational biologist, including PubMed, IEEE Xplore, the ACM digital library, ISI Web of Knowledge, Scopus, Citeseer, arXiv, DBLP, and Google Scholar. We illustrate the current process of using these libraries with a typical workflow, and highlight problems with managing data and metadata using URIs. We then examine a range of new applications such as Zotero, Mendeley, Mekentosj Papers, MyNCBI, CiteULike, Connotea, and HubMed that exploit the Web to make these digital libraries more personal, sociable, integrated, and accessible places. We conclude with how these applications may begin to help achieve a digital defrost, and discuss some of the issues that will help or hinder this in terms of making libraries on the Web warmer places in the future, becoming resources that are considerably more useful to both humans and machines.

Objective To evaluate the risk of postoperative bleeding and reintervention with the use of systemic steroids in patients undergoing tonsillectomy.

Design Systematic review and meta-analysis of randomised controlled trials.

Data sources Medline, Embase, Cochrane Library, Scopus, Web of Science, Intute, Biosis, OpenSIGLE, National Technical Information Service, and Google Scholar were searched. References from reviews identified in the search and from included studies were scanned.

Review methods Randomised controlled trials comparing the administration of systemic steroids during tonsillectomy with any other comparator were eligible. Primary outcome was postoperative bleeding. Secondary outcomes were the rate of admission for a bleeding episode, reintervention for a bleeding episode, blood transfusion, and mortality.

Results Of 1387 citations identified, 29 randomised controlled trials (n=2674) met all eligibility criteria. Seven studies presented a low risk of bias, but none was specifically designed to systematically identify postoperative bleeding. Administration of systemic steroids did not significantly increase the incidence of post-tonsillectomy bleeding (29 studies, n=2674 patients, odds ratio 0.96 (95% confidence interval 0.66 to 1.40), I²=0%). We observed a significant increase in the incidence of operative reinterventions for bleeding episodes in patients who received systemic steroids (12, n=1178, 2.27 (1.03 to 4.99), I²=0%). No deaths were reported. Sensitivity analyses were consistent with the findings.

Conclusions Although systemic steroids do not appear to increase bleeding events after tonsillectomy, their use is associated with a raised incidence of operative reinterventions for bleeding episodes, which may be related to increased severity of bleeding events. Systemic steroids should be used with caution, and the risks and benefits weighed, for the prevention of postoperative nausea and vomiting after tonsillectomy before further research is performed to clarify their condition of use.

Background

When searching for renal literature, nephrologists must choose between several different bibliographic databases. We compared the availability of renal clinical studies in six major bibliographic databases.

Methods

We gathered 151 renal systematic reviews, which collectively contained 2195 unique citations referencing primary studies in the form of journal articles, meeting articles or meeting abstracts published between 1963 and 2008. We searched for each citation in three subscription-free bibliographic databases (PubMed, Google Scholar and Scirus) and three subscription-based databases (EMBASE, Ovid-MEDLINE and ISI Web of Knowledge). For the subscription-free databases, we determined which full-text journal articles were available free of charge via links to the article source.

Results

The proportion of journal articles contained within each of the six databases ranged from 96 to 97%; results were similar for meeting articles. Availability of meeting abstracts was poor, ranging from 0 to 37% (P < 0.01) with ISI Web of Knowledge containing the largest proportion [37%, 95% confidence interval (95% CI) 32–43%]. Among the subscription-free databases, free access to full-text articles was highest in Google Scholar (38% free, 95% CI 36–41%), and was only marginally higher (39%) when all subscription-free databases were searched. After 2000, free access to full-text articles increased to 49%.

Conclusions

Over 99% of renal clinical journal articles are available in at least one major bibliographic database. Subscription-free databases provide free full-text access to almost half of the articles published after the year 2000, which may be of particular interest to clinicians in settings with limited access to subscription-based resources.

Background

PubMed is the most widely used method for searches of the medical literature, but fails to identify many relevant articles. Electronic citation tracking offers an alternative search method.

Methods

Articles investigating the role of depression in the aetiology and prognosis of coronary heart disease were sought through two methods: a) PubMed, and b) citation tracking where Science Citation Index was searched for all articles which cited ("forward citation tracking") or were cited by ("backward citation tracking") any of the articles in an index review. The number and quality of eligible articles identified by the two methods were compared.

Results

50 articles that were not already included in the index review met our inclusion criteria; 11 were identified through Science Citation Index alone, 8 through PubMed alone, and 31 through both methods. Articles identified by Science Citation Index alone were published in higher impact factor journals, were larger and were less likely to show a positive association.

Conclusion

Science Citation Index identified more eligible articles than PubMed, and these differed qualitatively. Failing to use citation tracking in a systematic review of observational studies may result in bias.

Background

Within the context of a European network dedicated to the study of sarcoma the relevant literature on sarcoma risk factors was collected by searching PubMed and Google Scholar, the two information storage and retrieval databases which can be accessed without charge. The present study aims to appraise the relative proficiency of PubMed and Google Scholar.

Findings

Unlike PubMed, Google Scholar does not allow a choice between "Human" and "Animal" studies, nor between "Classical" and other types of studies. As a result, searches with Google Scholar produced high numbers of citations that have to be filtered. Google Scholar resulted in a higher sensitivity (proportion of relevant articles, meeting the search criteria), while PubMed in a higher specificity (proportion of lower quality articles not meeting the criteria, that are not retrieved). Concordance between Google Scholar and PubMed was as low as 8%.

Conclusions

This study focused just on one topic. Although further studies are warranted, PM and GS appear to be complementary and their integration could greatly improve the search of references in medical research.

The use of quantitative metrics to gauge the impact of scholarly publications, authors, and disciplines is predicated on the availability of reliable usage and annotation data. Citation and download counts are widely available from digital libraries. However, current annotation systems rely on proprietary labels, refer to journals but not articles or authors, and are manually curated. To address these limitations, we propose a social framework based on crowdsourced annotations of scholars, designed to keep up with the rapidly evolving disciplinary and interdisciplinary landscape. We describe a system called Scholarometer, which provides a service to scholars by computing citation-based impact measures. This creates an incentive for users to provide disciplinary annotations of authors, which in turn can be used to compute disciplinary metrics. We first present the system architecture and several heuristics to deal with noisy bibliographic and annotation data. We report on data sharing and interactive visualization services enabled by Scholarometer. Usage statistics, illustrating the data collected and shared through the framework, suggest that the proposed crowdsourcing approach can be successful. Secondly, we illustrate how the disciplinary bibliometric indicators elicited by Scholarometer allow us to implement for the first time a universal impact measure proposed in the literature. Our evaluation suggests that this metric provides an effective means for comparing scholarly impact across disciplinary boundaries.

Background

It has been shown that large interdisciplinary teams working across geography are more likely to be impactful. We asked whether the physical proximity of collaborators remained a strong predictor of the scientific impact of their research as measured by citations of the resulting publications.

Methodology/Principal Findings

Articles published by Harvard investigators from 1993 to 2003 with at least two authors were identified in the domain of biomedical science. Each collaboration was geocoded to the precise three-dimensional location of its authors. Physical distances between any two coauthors were calculated and associated with corresponding citations. Relationship between distance of coauthors and citations for four author relationships (first-last, first-middle, last-middle, and middle-middle) were investigated at different spatial scales. At all sizes of collaborations (from two authors to dozens of authors), geographical proximity between first and last author is highly informative of impact at the microscale (i.e. within building) and beyond. The mean citation for first-last author relationship decreased as the distance between them increased in less than one km range as well as in the three categorized ranges (in the same building, same city, or different city). Such a trend was not seen in other three author relationships.

Conclusions/Significance

Despite the positive impact of emerging communication technologies on scientific research, our results provide striking evidence for the role of physical proximity as a predictor of the impact of collaborations.

Background:

The scientific research in urology and nephrology of China has developed significantly. The present study was designed to analyze the outputs of publications in urology and nephrology journals from three regions of China: mainland, Taiwan and Hong Kong.

Methods:

The numbers of articles, impact factors, citation reports and other indexes within this category between 2000 and 2009 were extracted for quantity and quality comparisons from PubMed and the ISI (Institute for Scientific Information-currently called the Thomson Reuters Web of Knowledge) database.

Results:

There were 3100 articles from the mainland (36.5%), Taiwan (46.8%) and Hong Kong (16.7%), and the increasing trend in each region was significant (p < 0.001). The accumulated impact factor and total citation of Taiwan exceeded the other two regions, while the average impact factor and citation of Hong Kong was highest. There were differences between the three regions on the most popular journals.

Interpretation:

Although the quantity of articles in urology and nephrology from the mainland has exceeded Taiwan and Hong Kong since 2008, there is a considerable gap in the quality of articles between the mainland and the other two regions.

In the 1970s Thomas McKeown and Archibald L Cochrane were two of the most influential voices in criticizing the dominance of medical thinking. A bibliometric study of the citations to McKeown's The Role of Medicine: Dream, Mirage or Nemesis and Cochrane's Effectiveness and Efficiency: Random Reflections on Health Services was performed from the publication of each book until 1988 to study how their ideas have been disseminated. During the study period 430 papers in the Science Citation Index or the Social Sciences Citation Index cited Cochrane's book, 133 cited McKeown's, and 166 cited both. The citations came mainly from original papers published in journals of internal medicine or public health and epidemiology (35%) and written by authors from the United States or the United Kingdom. Cochrane's book was cited most frequently in medical journals, suggesting a higher degree of penetration of his ideas among medical scientists. Although the dominance of original papers among the citations suggests that these books have been important in stimulating new knowledge, the main problems that McKeown and Cochrane identified--namely, the relatively small impact of clinical medicine on health outcomes and the poor use of scientific methods in clinical practice--are still with us.

Background

Author self-citation is the practice of citing one's previous publications in a new publication. Its extent is unknown. We studied author self-citation, choosing the major clinical field of diabetes mellitus to represent the general medical literature.

Methods

We identified every article about diabetes mellitus in 170 hand-searched clinical journals published in 2000. For every article, we recorded the bibliographic citation and publication type (original or review article) and assessed the methodologic rigour. Citation information was obtained from the ISI Web of Knowledge in April 2003.

Results

Of 49 028 articles, 289 were about diabetes mellitus and had citation information. Citation counts ranged from 0 to 347 (median 6, interquartile range [IQR] 2–12). Author self-citation counts ranged from 0 to 16 (median 1, IQR 0–2). Author self-citations accounted for an average of 18% (95% confidence interval [CI] 15%–21%) and a median of 7% (95% CI 5%– 11%) of all citations of each publication that was cited at least once (n = 266). Original articles had double the mean proportion of author self-citations compared with review articles (19% v. 9%; median 7% v. 0%, difference 7%, 95% CI 0– 10%). Methodologic rigour and review type were not significantly associated with subsequent author self-citation.

Interpretation

Nearly one-fifth of all citations to articles about diabetes mellitus in clinical journals in the year 2000 were author self-citations. The frequency of self-citation was not associated with the quality of publications. These findings are likely applicable to the general clinical medicine literature and may have important implications for the assessment of journal or publication importance and the process of scientific discovery.

AIM: To analyze papers published in the World Journal of Gastroenterology (WJG) from 2006 to 2007. We investigated the highly cited papers for geographic distribution of the cited authors, as well as the distribution of the citing journals and year of citation.

METHODS: Papers published in WJG from 2006 to 2007 and their citations were retrieved from the Science Citation Index Expanded (SCIE). The papers and their citations were analyzed according to bibliometric methods, including the number of citations for a given paper, the distribution of the highly cited papers, the geographic distribution of the cited authors, and the years of citation.

RESULTS: Two thousand five hundred and six papers published in WJG from 2006 to 2007 were collected through SCIE, and 2335 of these were categorized as articles, reviews or proceedings. In 2006 and 2007, the average citation rate was 85.08% and 70.48%, respectively, and the average number of citations per paper was 4.33 and 2.51. Among the 2506 papers, 1963 were cited 8788 times by other articles. The mean number of citations per paper was 3.51. The papers with over three citations accounted for 54.72% of all those that were cited, and the total number of citations accounted for 85.38% of the total of 8788 citations. Thirteen papers were cited over 30 times and the highest number of citations for any one paper was 98. The cited authors came from 70 different countries or regions, with China, Japan and the United States being the most frequent. The highest average citation rate and number of citations per paper were for authors from Canada (96.30%, 6.89), Hungary (92.31%, 5.62), Australia (88.46%, 5.46), Germany (87.04%, 5.33), and Spain (87.50%, 5.11). The impact factor was 2.081 and the self-citation rate was 9.41% in 2008. The papers published in WJG in 2006-2007 were cited by 1597 journals.

CONCLUSION: The papers in WJG have a high number of citations, and have been cited in numerous journals by authors from various countries. The results imply that WJG has an influential academic profile in gastroenterology around the world.

Objective:

This research measures the effectiveness of the practice of correction and republication of invalidated articles in the biomedical literature by analyzing the rate of citation of the flawed and corrected versions of scholarly articles over time. If the practice of correction and republication is effective, then the incidence of citation of flawed versions should diminish over time and increased incidence of citation of the republication should be observed.

Methods:

This is a bibliometric study using citation analysis and statistical analysis of pairs of flawed and corrected articles in MEDLINE and Web of Science.

Results:

The difference between citation levels of flawed originals and corrected republications does not approach statistical significance until eight to twelve years post-republication. Results showed substantial variability among bibliographic sources in their provision of authoritative bibliographic information.

Conclusions:

Correction and republication is a marginally effective biblioremediative practice. The data suggest that inappropriate citation behavior may be partly attributable to author ignorance.

Objectives:

The research identified the publication types and ages most frequently cited in the infectious diseases literature and the most commonly cited journals.

Methods:

From 2008–2010, 5,056 articles in 5 infectious diseases journals cited 166,650 items. Two random samples were drawn: one (n = 1,060) from the total set of citations and one (n = 1,060) from the citations to journal articles. For each sample citation, publication type and date, age of cited item, and inclusion of uniform resource locator (URL) were collected. For each item in the cited journal articles sample, journal title, publication date, and age of the cited article were collected. Bradford zones were used for further analysis.

Results:

Journal articles (91%, n = 963) made up the bulk of cited items, followed by miscellaneous items (4.6%, n = 49). Dates of publication for cited items ranged from 1933–2010 (mean = 2001, mode = 2007). Over half (50.2%, n = 483) of cited journal articles were published within the previous 5 years. The journal article citations included 358 unique journal titles.

Discussion:

The citations to current and older publications in a range of disciplines, heavy citation of journals, and citation of miscellaneous and government documents revealed the depth and breadth of resources needed for the study of infectious diseases.