Table 2.

 Characteristics of included meta-analyses. Values are number (percentage) of meta-analyses unless stated otherwise

Characteristic	Meta-analyses (n=124)
Financial ties with one drug company	49 (40)
Mean (range), median quality score*	6.66 (0-17), 7
Published in journal supplement	21 (17)
Searched or included non-English literature	11 (9)
Described process of data abstraction	27 (22)
Included non-randomised controlled trials	38 (31)
Included unpublished studies	5 (4)
Included studies that used only placebo group as control group	27 (22)
Focused on newer class of drug	51 (41)
Used surrogate outcomes only	51 (41)
Used composite outcomes only	3 (2)
Carried out evaluations of heterogeneity	62 (50)
Carried out sensitivity analyses	70 (56)

*Score was continuous variable from 0-18, with higher scores indicating better quality and lower scores indicating worse quality.