Comparison 2. Incidence of MI over all time periods.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
2.1 Heparin vs placebo or untreated control	6	2426	Risk Ratio (M‐H, Fixed, 95% CI)	0.40 [0.25, 0.63]
2.1.1 LMWH	2	1602	Risk Ratio (M‐H, Fixed, 95% CI)	0.28 [0.14, 0.55]
2.1.2 UFH	3	541	Risk Ratio (M‐H, Fixed, 95% CI)	0.55 [0.23, 1.34]
2.1.3 UFH + warfarin	2	283	Risk Ratio (M‐H, Fixed, 95% CI)	0.63 [0.25, 1.62]