Objective: To determine if there was statistically significant geographic v
ariation in the number of authors on abstracts of the 1999 Radiological Soc
iety of North America (RSNA) Scientific Assembly. Methods: Information on t
ype of presentation, number of authors listed in each presentation and coun
try of origin was obtained for 2450 abstracts from the 1999 RSNA Scientific
Assembly (1292 for scientific sessions, 1158 for scientific exhibitions).
Results: In scientific sessions, there were significantly more multiauthor
(> 6 authors) presentations from Japan (32%, p < 0.001) and Germany (19%, p
= 0.004) than there were from North America (United States and Canada) (11
%). There were also significantly more multiauthor scientific exhibitions f
rom Japan (29%, p < 0.001) than from North America (9%). Overall, the perce
ntages of multiauthor presentations from Japan (30%, p < 0.001) and Germany
(18%, p < 0.001) were significantly higher than those from North America (
10%). Conclusion: There seems to be significant geographic variation in the
number of authors credited on scientific presentations.