Clinical Investigation
Success Breeds Success: Authorship Distribution in the Red Journal, 1975-2011

Presented in part at the 52nd Annual Meeting of the American Society for Radiation Oncology (ASTRO) in San Diego, CA, October 31-November 4, 2010.
https://doi.org/10.1016/j.ijrobp.2012.03.012Get rights and content

Purpose

Publication analysis has value in evaluating the mechanics of academic efforts in specific scientific communities. The specific aim of this study was to evaluate whether established bibliometric patterns seen in other academic fields were likewise observed in radiation oncology publication parameters.

Methods and Materials

We used a commercial bibliographic database to analyze all publications in Red Journal, or International Journal of Radiation Oncology Biology Physics (IJROBP), the New England Journal of Medicine (NEJM), the Journal of Clinical Oncology (JCO), and Radiology (Rad) between January 1, 1975 and May 18, 2011. Power-law (Lotka's law or 1/n2) conformance was assessed. Curve fit analysis was then performed.

Results

In all 4 journals, a total of 219,476 authors were responsible for 62,232 articles. Of those, 79,810 authors published 13,772 articles in IJROBP, with 79,446/16,707 authors/articles in NEJM, 106,984/11,920 authors/articles in JCO and 90,325/19,745 authors/articles in Rad. The mean ± standard deviation of authors per publication was 5.74 ± 4.61 overall. There were 5.8 ± 3.53, 4.8 ± 5.7, 8.9 ± 3.53, and 4.6 ± 2.8 authors per article in IJROBP, NEJM, JCO, and Rad, respectively (P<.001). The number of authors publishing n articles was 1/n2.02 of those publishing 1 article in IJROBP, 1/n2.52 in NEJM, 1/n1.97 in JCO, and 1/n2.16 in Rad.

Conclusions

Bibliometric analysis shows that authorship distributions in IJROBP approximate those of the scientific literature in comparable scientific journals. Our results suggest that the majority of publications in the field of radiation oncology are produced by a small but highly productive group of authors.

Introduction

Within bibliometric analysis, it is a well-established observation that the majority of scientific contributors proffer no more than 1 manuscript, and that a small but active percentage of authors are disproportionately productive. Lotka's Law summarizes this observation, stating that the number of authors making n contributions is equal to about 1/nL of those publishing 1 article, where L is approximately 2. Therefore, the percentage of all contributors contributing a single article is approximately 60%, the percentage contributing 2 articles is 15%, and so on. Alfred Lotka originally described this relationship by analyzing publications in the Decennial Index to Chemical Abstracts 1907-16 and Auerbach's Geschichtstafeln der Physik submitted by chemists and physicists in the early 20th century (1).

Since this original publication in 1926, many academic fields have attempted to apply this power law to publication productivity. Obstetrics and gynecology, neuroscience, dental science, psychiatry, and epidemiology have all attempted to apply Lotka's Law to authorship distributions within their respective fields 2, 3, 4, 5, 6, 7. Most investigators have found that authorship rates abide by Lotka's Law whether analyzed by field 2, 3, 4, journal (7), or subject matter 5, 6. The wide applicability of this bibliometric phenomenon suggests that it may also provide insight into other competitive human activities.

Other surrogates have been used to evaluate and compare academic productivity in the field of radiation oncology. Choi et al evaluated the productivity of radiation oncologists using the Hirsch index and found a breakpoint, h=15, separating junior and senior faculty (8). Morgan et al evaluated first-authorship rates among radiation oncology residents and ranked residency programs based on productivity (9). To our knowledge, there are no currently published studies examining authorship distribution in a single medical journal, or in radiation oncology specifically.

This study aimed to tabulate authorship statistics in a major radiation oncology journal, the International Journal of Radiation Oncology Biology Physics (IJROBP), as part of a larger effort to quantify academic field-specific parameters of scientific activity so as to determine a baseline metric for future comparison. To this end, we sought to assess bibliometric patterns in academic field-specific journals in similar, related specialties and in prominent cross-disciplinary journals. Specifically, we used a primary diagnostic radiology journal, Radiology (Rad); an oncology journal, the Journal of Clinical Oncology (JCO); and a high-impact medical journal attracting authors across disciplines, the New England Journal of Medicine (NEJM). Additionally, we wished to determine whether authorship distribution(s) in said journals approximate Lotka's Law. We aimed to examine other trends in authorship including the percentage of articles written by a single author and the mean number of authors per article. Finally, we aimed to identify, albeit in a limited fashion, the characteristics of individuals with the highest publication rates in IJROBP and to discuss the potential implications of these observations.

Section snippets

Methods and Materials

The journals chosen for bibliometric analysis were IJROBP (ISSN 0360-3016), NEJM (ISSN 0028-4793), JCO (ISSN 0732-183X), and Rad (ISSN 0033-8419).

A search was performed using a commercial bibliographic database (SCOPUS, Elsevier B.V., Amsterdam, Netherlands). All publications from 1975, or earliest publication if the journal was founded after 1975, until May 18, 2011, as reported in SCOPUS, were downloaded and compiled in a spreadsheet as comma-separated-values. All publications appearing in

Results

A total of 219,476 authors were responsible for 109,733 publications in all 4 journals (including articles, conference papers, errata, letters, notes, reviews, and short surveys). Of those, 79,810 authors published 18,779 publications in IJROBP, 79,446 published 48,249 publications in NEJM, 106,984 published 18,269 publications in JCO, and 90,325 published 19,745 publications in Rad. After the exclusion of conference papers, editorials, errata, letters, notes, reviews, and short surveys, there

Discussion

To our knowledge, this study represents the first bibliometric analysis of authorship rates in a major radiation oncology, oncology, or radiology journal. We found that authorship in IJROBP does approximate Lotka's Law, and publication distribution is similar to that of major journals in the fields of radiology, oncology, and general medicine. One interesting observation is that the percentage of authors publishing 1 article vs 2, 3, and so on does not seem to vary substantially with the number

Conclusions

We have demonstrated through bibliometric analysis that authorship distributions in radiation oncology journals approximate those of the scientific literature at large and of power-law relationships generally. Our results suggest that publications in the field of radiation oncology and in other disciplines are produced by a relatively small but highly productive subset of authors.

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