(A) Number of retracted articles for specific causes by year of retraction. (B) Percentage of published articles retracted for fraud or suspected fraud by year of publication.

Country of origin of publications retracted for fraud or suspected fraud (A), plagiarism (B), or duplicate publication (C).

Relation of journal-impact factor to retractions for fraud or suspected fraud, error, and plagiarism, or duplicate publication. Journal-impact factor showed a highly significant correlation with the number of retractions for fraud or suspected fraud (A) (n = 889 articles in 324 journals, R² = 0.08664, P < 0.0001) and error (B) (n = 437 articles in 218 journals, R² = 0.1142, P < 0.0001), and a slight correlation with the number of retractions for plagiarism or duplicate publication (C) (n = 490 articles in 357 journals, R² = 0.01420, P = 0.0243). The mean journal-impact factor of articles retracted because of fraud/suspected fraud or error was significantly different from that of papers retracted because of plagiarism or duplicate publication (D) (error bars ± SEM, P < 0.0001).

(A) Time-to-retraction as a function of year of retraction. R² = 0.1236, P = 0.0414. (B) Time-to-retraction as a function of impact factor. Journal-impact factor correlated inversely with time-to-retraction for articles retracted because of fraud (n = 697, R² = 0.01441, P = 0.0015) but not other causes.