Comparison 2. Thoracic surgery: symptomatic VTE.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Heparin versus inactive control	3	2458	Risk Ratio (IV, Random, 95% CI)	6.71 [0.40, 112.65]
1.1 UFH versus placebo	1	29	Risk Ratio (IV, Random, 95% CI)	0.0 [0.0, 0.0]
1.2 UFH versus no UFH	2	2429	Risk Ratio (IV, Random, 95% CI)	6.71 [0.40, 112.65]
2 UFH versus defibrotide	1		Risk Ratio (IV, Random, 95% CI)	Totals not selected
3 UFH versus LMWH	1		Risk Ratio (IV, Random, 95% CI)	Totals not selected
4 Fixed‐dose LMWH versus weight‐adjusted dose LMWH	1		Risk Ratio (IV, Random, 95% CI)	Totals not selected