The rise of multiple imputation: a review of the reporting and implementation of the method in medical research

Table 1 Number of articles using multiple imputation from January 2008 to December 2013 by type of study

	Journal’s name
Type of studies	Lancet	New England Journal of Medicine	All Studies
	(n = 58)	(n = 45)	(n = 103)
Trials
Randomised controlled trials	35	34	69
Non-randomised controlled trials^a	2	2	4
Total	37	36	73
Observational studies
Prospective studies	11	7	18
Retrospective studies^b	6	1	7
Cross-sectional studies	3	0	3
Case–control studies	1	1	2
Total	21	9	30

^aQuasi- experimental studies; ^bRetrospective studies- these are studies which performed a retrospective analysis of routinely collected data.

ISSN: 1471-2288