Duplicate publications: A sample of redundancy in the Journal of Urology

Purpose: Redundant publications occur when authors publish a partial or complete duplicate of data from an existing manuscript. The push for academic advancement in medicine may result in redundant publications that erode the quality of literature. We sampled the extent of redundancy within the Journal of Urology. Methods: Original articles published in the Journal of Urology in 2006 were reviewed. MEDLINE was used to identify suspected duplicate publications by combining the last names of the first, second and last authors with keywords provided by the article. Results were limited to 2004 to 2008. Two investigators reviewed the suspected duplicate publications and classified them as duplicate, probable duplicate and salami-slicing. Results: We screened 723 original articles. Of these original articles, 13 (1.8%) had some form of redundancy. One (0.1%) original article had a duplicate article, 5 (0.7%) original articles had probable duplicates, and 7 (1%) original articles were salami-sliced. The proportion of redundant articles published prior to, and following, their 2006 index article was 5/13 (38.5%) and 7/13 (53.8%), respectively. One duplicate (7.7%) was published in the same month as its index. Conclusion: Detection of redundant publications is a laborious process for reviewers and editors. This sampling of the Journal of Urology revealed that the duplication rate in this journal is small, but significant. Further assessment of the urological literature is warranted.