Self-plagiarism

This is the authors' abstract. We don't add key points for this paper.

Dear Editor BJS published an article titled ‘Effects of short stitch technique for midline abdominal closure on incisional hernia (ESTOIH): randomized clinical trial’1. This article cites another article published in the journal Hernia2. There are lots of similarities in the introduction, methodology, study protocol, and intervention. Some sentences/paragraphs are almost ‘copy–pasted’. The cohort, sample size calculation, Tables 1 and 2 in Fortelny et al.1 and Tables 1 and 4 in Albertsmeier et al.2 respectively are exactly the same. It is not clear whether the authors have taken written permission from Hernia2 for reproducing the table. The data on 192 and 181 patients were available for analysis at 3 months, but data on 210 and 204 (BJS) were available at the end of 1 year. As the follow-up period increases, we expect data for a smaller number (or at most the same number) of patients to be available for analysis. How were data on more patients added at a later date? Of 215 and 210 patients (BJS CONSORT) allocated to receive the intervention, data from 33 and 51 patients were not available for various reasons, and 5 and 6 patients were lost to follow-up. At the end, data on 210 and 204 patients were analysed. How can this be possible? This is neither an intention-to-treat protocol nor per-protocol analysis. The BJS article states that a per-protocol analysis was done, in which case the number of patients available for final analysis must have been 182 and 159. We question how these two articles by the same group of authors with the same cohort and the same data have been published in two different reputable journals with high impact factors escaping the plagiarism check software of the journal. We feel this is self-plagiarism as separately publishing multiple similar papers on the same study data in different journals constitutes self-plagiarism.