Trends in Authorship Patterns in High-Impact Radiology Publications, 1980–2013

Abstract

Concerns have been raised about authorship inflation in medical literature. The purpose of this study was to determine how the number of authors per radiology article has changed over time with regard to study type and geographic factors. We collected data on study type, authorship count, and the country of the corresponding author for a sample of articles published in Radiology, American Journal of Roentgenology, and European Radiology in 1980, 1990, 2000, and 2013. Only original research and review articles were considered. We computed trends in the mean number of authors per article for each journal and compared authorship trends between study types and geographic region. The study did not involve human subjects and was therefore exempt from institutional board review at our institution. A total of 682 articles were reviewed, of which 572 were original research articles (83.9%) and 110 review articles (16.1%). The overall number of authors per article doubled from 3.6 in 1980 to 7.3 in 2013 (P < .001). From 1990 to 2013, the largest absolute increase in authorship count was in Radiology (4.4-8.1, 84.1%, P < .001). The largest increase in authorship occurred in original research articles (3.7-7.8, 111%, P < .001). Although authorship counts were greatest in Asia over most study period, growth in authorship count was highest in Europe. Authorship count has dramatically increased in radiology journals in the last 3 decades, particularly in original research articles and in Europe.