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Table 2 Summary characteristic of included studies

From: Recent meta-analyses neglect previous systematic reviews and meta-analyses about the same topic: a systematic examination

Journal

Recent

Previous

Annals of Internal Medicine

9

17%

54

22%

British Medical Journal

24

46%

117

48%

JAMA

7

13%

32

13%

New England Journal of Medicine

1

2%

9

4%

PLOS Medicine

5

10%

12

5%

The Lancet

6

12%

18

7%

Total:

52

 

242

 

Mean AMSTAR score for recent meta-analyses

8.5 (SD 1.5)

Mean impact factor for previous studies

7.7 (SD 8.8)

Previous SRs with meta-analysis

218

Previous SRs without meta-analysis

24

Number of previous studies for a recent meta-analysis

0 to 28 (mean 4.65; SD 4.65)

Mean length of time from publication year previous to recent study

3.6 years (SD 2.5)

Mean similarity score between previous and recent studies

1.8 points (SD 1.1, range 0 to 4)

  1. ‘Recent’ refers to the initially identified meta-analyses and ‘previous’ refers to the previous meta-analyses or systematic reviews (SRs) on the same topic. More detailed information on all the individual studies is presented in Additional files 5 and 6. SD, standard deviation.