Table 1

Classification of retractions (N=312)

Code	Reason	Sub-category	N	%
1	Honest error	(a) based on incorrect/fraudulent^* data	10	28
		(b) research error (eg, wrong cell line)	44
		(c) calculation error/inaccurate data	33
2	Could not replicate findings	(a) same authors	31	11
2	Could not replicate findings	(b) different authors	4
3	Journal (administrative) error		3	1
4	Redundant publication	(a) complete (ie, duplicate/triplicate publication)	34	17
4	Redundant publication	(b) partial (ie, overlapping publications)	20
5	Plagiarism	Amount unspecified	6	16
		(a) total (ie, whole paper copied)	4
		(b) partial—data only	7
		(c) partial—text only	18
		(d) partial—data and text	14
6	Data used without permission/author dispute		17	5
7	Fabricated data		16	5
8	Falsified data		13	4
9	Ethical problems with research		4	1
10	Misconduct (unspecified)		10	2
11	Inaccurate/misleading reporting		12	4
12	No reason/unclear		17	5

* For example, calculations based on published work by another group that later turned out to be fraudulent, therefore the inclusion of the fraudulent data was an honest error on the part of the second group of researchers.