Comparison 1. LMWH versus placebo.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 All VTE	7	1728	Odds Ratio (M‐H, Fixed, 95% CI)	0.38 [0.26, 0.54]
2 All DVT	7	1728	Odds Ratio (M‐H, Fixed, 95% CI)	0.39 [0.27, 0.55]
3 Proximal DVT	7	1728	Odds Ratio (M‐H, Fixed, 95% CI)	0.22 [0.10, 0.47]
4 Symptomatic VTE	7	1728	Odds Ratio (M‐H, Fixed, 95% CI)	0.30 [0.08, 1.11]
5 Bleeding complications	7	2239	Odds Ratio (M‐H, Fixed, 95% CI)	1.10 [0.67, 1.81]
6 All VTE (Subgroup analysis open only)	6	1503	Odds Ratio (M‐H, Fixed, 95% CI)	0.42 [0.29, 0.60]
7 All DVT (Subgroup analysis open only)	6	1503	Odds Ratio (M‐H, Fixed, 95% CI)	0.43 [0.30, 0.62]
8 All VTE (Sensitivity analysis unpublished)	6	1620	Odds Ratio (M‐H, Fixed, 95% CI)	0.38 [0.27, 0.56]
9 All DVT (Sensitivity analysis unpublished)	6	1620	Odds Ratio (M‐H, Fixed, 95% CI)	0.40 [0.27, 0.58]
10 Mortality at 90 days	7	1881	Odds Ratio (M‐H, Fixed, 95% CI)	1.15 [0.72, 1.84]