Hot topics and trends in cardiovascular research.

AIMS: Comprehensive data on research undertaken in cardiovascular medicine can inform the scientific community and can support policy building. We used the publication output from 2004 to 2013 and the 2014 references to these documents, to identify research topics and trends in the field of cardiovascular disease. METHODS AND RESULTS: Text fragments were extracted from the titles and abstracts of 478 000 publications using natural language processing. Through machine-learning algorithms, these text fragments combined to identify specific topics across all publications. A second method, which included cross-references, assigned each publication document to a specific cluster. Experts named the topics and document clusters based on various outputs from these semi-automatic methods. We identified and labelled 175 cardiovascular topics and 20 large document clusters, with concordance between the approaches. Overarching, strongly growing topics in clinical and population sciences are evidence-based guidance for treatment, research on outcomes, prognosis, and risk factors. 'Hot' topics include novel treatments in valve disease and in coronary artery disease, and imaging. Basic research decreases its share over time but sees substantial growth of research on stem cells and tissue engineering, as well as in translational research. Inflammation, biomarkers, metabolic syndrome, obesity, and lipids are hot topics across population, clinical and basic research, supporting integration across the cardiovascular field. CONCLUSION: Growth in clinical and population research emphasizes improving patient outcomes through novel treatments, risk stratification, and prevention. Translation and innovation redefine basic research in cardiovascular disease. Medical need, funding and publishing policies, and scientific opportunities are potential drivers for these evolutions.

A Changing Landscape in Cardiovascular Research Publication Output: Bridging the Translational Gap.

The concern about predominance of basic discovery research and lack of translation into clinical medicine, and segregation between these research communities, led the authors to study these research communities through mapping networks of publications and cross-references. Cardiovascular research from 1993 to 2013 was published in 565 journals, including 104 new journals. Only 50% were published in core cardiovascular journals, such as the Journal of the American College of Cardiology, whereas one-half of cardiovascular publications were found in broader biomedical/multidisciplinary journals. The growth of the clinical journal community and merging into one broad journal community suggests a decreasing dichotomy between basic/preclinical and clinical research, potentially contributing to bridging the translational gap.

Co-Citation Analysis of Articles Published in Substance Abuse Journals: Intellectual Structure and Research Fields (2001-2012).

OBJECTIVE: The purpose of this study is to introduce a new methodology in the field of substance abuse, namely, co-citation analysis, which uses the bibliographic references of publications to establish the main thematic areas being researched and to identify the seminal documents that have contributed to establishing the intellectual foundation of the discipline at the present time. METHOD: We identified all bibliographic references that were cited in documents published in the substance abuse journals included in the Journal Citation Reports in the 2001-2012 period, generating a co-citation matrix. This matrix was used to perform a co-citation network analysis. RESULTS: The co-citation network analysis led to the identification of 56 prominent research clusters that bring together 698 documents; their subject matter constitutes the foundation of the discipline in the field's journals. CONCLUSIONS: Substance abuse research is dominated by a few core topics; chief among them are tools for measuring and diagnosing dependence, as well as therapeutic approaches to treat alcohol abuse and nicotine addiction. Other areas of note include epidemiological studies, research on drug user motivation (particularly among young people), binge drinking, social support mediators and networks, opioid dependence, consumption and effects of cannabis, basic research on brain damage, genetic factors associated with substance use, and the physiological and neurological determinants of abstinence syndrome. The main works of reference that we identified were published in a small number of journals, which establish the intellectual, conceptual, and methodological basis of the discipline.

Interdisciplinarity and impact: distinct effects of variety, balance, and disparity.

Interdisciplinary research is increasingly recognized as the solution to today's challenging scientific and societal problems, but the relationship between interdisciplinary research and scientific impact is still unclear. This paper studies the association between the degree of interdisciplinarity and the number of citations at the paper level. Different from previous studies compositing various aspects of interdisciplinarity into a single indicator, we use factor analysis to uncover distinct dimensions of interdisciplinarity corresponding to variety, balance, and disparity. We estimate Poisson models with journal fixed effects and robust standard errors to analyze the divergent relationships between these three factors and citations. We find that long-term (13-year) citations (1) increase at an increasing rate with variety, (2) decrease with balance, and (3) increase at a decreasing rate with disparity. Furthermore, interdisciplinarity also affects the process of citation accumulation: (1) although variety and disparity have positive effects on long-term citations, they have negative effects on short-term (3-year) citations, and (2) although balance has a negative effect on long-term citations, its negative effect is insignificant in the short run. These findings have important implications for interdisciplinary research and science policy.

A new generation of relational charts for comparative assessment of citation impact.

A common problem in comparative bibliometric studies at the meso and micro level is the differentiation and specialization of research profiles of the objects of analysis at lower levels of aggregation. In this study, institutional profile clusters are used to examine which level of the hierarchical subject classification should preferably be used to build subject-normalized citation indicators. It is shown that a set of properly normalized indicators can serve as a basis of comparative assessment within and even among different clusters, provided that their profiles still overlap and such comparison is thus meaningful. Using the example of 24 European universities, a new version of relational charts is presented for the comparative assessment of citation impact.