Comparison 8. Incidence of thrombocytopenia over all time periods.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
8.1 Heparin vs placebo or untreated control	2	1717	Risk Ratio (M‐H, Random, 95% CI)	0.20 [0.01, 4.24]
8.1.1 LMWH	2	1610	Risk Ratio (M‐H, Random, 95% CI)	0.20 [0.01, 4.24]
8.1.2 UFH	1	107	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
8.1.3 UFH + warfarin	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable