Characteristics of retracted systematic reviews and meta-analyses in the biomedical literature

The number of retracted reviews, including systematic reviews and meta-analyses, in the biomedical literature has increased dramatically in recent years. There has not yet been a systematic study to clarify the characteristics of retracted reviews. Present study determined trends in biomedical reviews, particularly with respect to reasons for retraction and geographical origin. Reviews were collated from Medline and Cochrane Library searches. Reasons for retraction were catalogued based on information retrieved via PubMed, Google, and journal websites. A total of 171 retracted non-Cochrane reviews and 439 Cochrane reviews were included. The most common reasons for retraction of non-Cochrane reviews were invalid review (n = 70), error (n = 36), and plagiarism (n = 20). Chinese authors produced a distinctively large number of reviews retracted for a faked review process and most retracted meta-analyses from areas of biochemistry molecular biology, oncology, genetics heredity and etc. Cochrane review retraction reasons included principally updating issues (n = 382), errors (n = 26), and sponsorship policy issues (n = 13). The number of retracted reviews in the biomedical literature, especially from Chinese authors, has surged since 2005. The major reasons for these retractions were related to updating among Cochrane systematic reviews but were related to misconduct among non-Cochrane systematic reviews. The present results highlight the need misconduct prevention measures.