Identifying common patterns in journals that retracted papers from paper mills: a cross-sectional study

To characterize journals that published and retracted articles retracted for having originated from paper mills and examine associations between paper mill retraction frequency and journal characteristics.

Retraction Watch database was used to identify papers retracted due to originating from paper mills and journals, between January 2020 and December 2022. Data on the total number of articles and journal characteristics were obtained from Web of Science and Journal Citation Reports. Journals were classified based on the frequency of retracted paper mill papers (1, 2-9, ≥ 10 retractions). Logistic regressions were conducted to explore associations between retraction frequency and journal characteristics.

One hundred forty-two journals were identified that retracted 2,051 articles from paper mills. Among these, 71 (50%) journals had 1 retraction, 36 (25.4%) had 2-9 retractions, and 35 (24.6%) had ≥ 10 retractions; 4 (2.8%) journals had > 100 retractions. These journals, regardless of paper mill retraction number, were mainly in the second (35.2%) and third (29.6%) quartiles by impact factor. Medicine and health emerged as the predominant subject area, comprising 61.2% of all indexed journal categories. Comparing journals with one retraction to those with ten or more, the proportion of open access articles (72.6% vs. 19.2%) and median editorial times (86 vs. 116 days) differed across groups, although these differences were not statistically significant. An inverse correlation was observed between the proportion of paper mill papers and original articles (Spearman's Rho = -0.1891, 95%CI -0.370 to -0.008). Logistic regressions found no significant association between paper mill retraction number and other variables.

This study suggests that paper mill retractions are concentrated in a small number of journals with common characteristics: high open access rates, intermediate impact factor quartiles, a high volume of citable items, and classification in medicine and health categories. Short editorial times may indicate a higher presence of paper mill publications, but more research is needed to examine this factor in depth, as well as the possible influence of acceptance rates.