Inaccurate retraction notice for meta-analysis by Iwamoto et al

Dear Editor,
The retraction notice for the meta‐analysis co‐authored by Drs Jun Iwamoto, Tsuyoshi Takeda and Hideo Matsumoto, affiliated to Keio University in Japan, oversimplifies a complex situation and might be misinterpreted by readers.1 It states that “extensive duplication of previously published material” was the reason for the retraction of the 3 trials contributing to the meta‐analysis, each of which was led by Dr Sato and co‐authored by Dr Iwamoto. Although the retraction notices for 2 trials describe self‐plagiarism,2, 3 one retraction notice also states that there was authorship misconduct.3 Another retraction notice discloses concerns about data integrity, which the co‐authors, including Dr Iwamoto, could not satisfactorily resolve,2 and another discloses that the trial was fraudulent.4, 5