Trend Toward an Increase in Authorship for Leading Radiology Journals.
OBJECTIVE
The purpose of this study was to determine authorship trends in two leading radiology journals over the past 2 decades.


METHODS
All original articles (n = 5195) published in AJR and Radiology for the periods 1991-1993, 2001-2003, and 2011-2013 were reviewed. The following variables were extrapolated from each article: number of authors, radiologic subspecialty, and country of origin. The number of authors listed per article was correlated with the publication period, journal, radiologic subspecialty, and country of origin.


RESULTS
The mean number of authors per article increased from 5.1 in 1991-1993 to 6.2 in 2001-2003 and to 7.1 in 2011-2013 across both journals (p < 0.0001). Both AJR and Radiology had statistically significant increases in the number of authors per article over time, but the number of authors per article in Radiology was significantly higher than that in AJR (p < 0.0001 for all study periods). The number of authors per article significantly increased for all radiologic subspecialties. The mean numbers of authors per article by country of origin are as follows: Italy, 8.3; Japan, 7.6; France, 7.5; Germany, 7.4; China, 7.3; Austria, 7.2; and South Korea, 6.8. These were significantly higher than the mean number of authors from Switzerland, which was 6.3.


CONCLUSIONS
The number of authors significantly and consistently increased in two leading radiology journals over the past 2 decades.
1 All authors: Department of Radiology, Kangdong Seong-Sim Hospital, Hallym University College of Medicine, 150, Seongan-ro, Gangdong-Gu, Seoul, 134-701, Korea.
Sora
S
Baek
1 All authors: Department of Radiology, Kangdong Seong-Sim Hospital, Hallym University College of Medicine, 150, Seongan-ro, Gangdong-Gu, Seoul, 134-701, Korea.
Dae Young
DY
Yoon
1 All authors: Department of Radiology, Kangdong Seong-Sim Hospital, Hallym University College of Medicine, 150, Seongan-ro, Gangdong-Gu, Seoul, 134-701, Korea.
Young Kwon
YK
Cho
1 All authors: Department of Radiology, Kangdong Seong-Sim Hospital, Hallym University College of Medicine, 150, Seongan-ro, Gangdong-Gu, Seoul, 134-701, Korea.
Eun Joo
EJ
Yun
1 All authors: Department of Radiology, Kangdong Seong-Sim Hospital, Hallym University College of Medicine, 150, Seongan-ro, Gangdong-Gu, Seoul, 134-701, Korea.
Young Lan
YL
Seo
1 All authors: Department of Radiology, Kangdong Seong-Sim Hospital, Hallym University College of Medicine, 150, Seongan-ro, Gangdong-Gu, Seoul, 134-701, Korea.
Kyoung Ja
KJ
Lim
1 All authors: Department of Radiology, Kangdong Seong-Sim Hospital, Hallym University College of Medicine, 150, Seongan-ro, Gangdong-Gu, Seoul, 134-701, Korea.
Chul Soon
CS
Choi
D001319:Authorship; D015706:Bibliometrics; D006801:Humans; D010506:Periodicals as Topic / Q000706:statistics & numerical data* / Q000639:trends*; D011643:Publishing / Q000706:statistics & numerical data* / Q000639:trends*; D011871:Radiology
authorship; radiology and radiologists; research