Comparison 8. LMWH versus UFH: all randomised controlled trials with adequate concealment of allocation.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Incidence of recurrent venous thromboembolism during initial treatment	10	4862	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.72 [0.50, 1.05]
1.1 Nadroparin versus unfractionated heparin	3	716	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.50 [0.18, 1.39]
1.2 Tinzaparin versus unfractionated heparin	1	612	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.52 [0.26, 8.80]
1.3 Enoxaparin versus unfractionated heparin	3	1034	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.48 [0.24, 0.96]
1.4 Reviparin versus unfractionated heparin	1	1021	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.07 [0.52, 2.19]
1.5 Certoparin versus unfractionated heparin	2	1479	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.79 [0.40, 1.58]
2 Incidence of recurrent venous thromboembolism at the end of follow‐up	14	6984	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.76 [0.60, 0.96]
2.1 Nadroparin versus unfractionated heparin	4	1436	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.70 [0.45, 1.10]
2.2 Tinzaparin versus unfractionated heparin	2	1044	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.54 [0.26, 1.08]
2.3 Ardeparin versus unfractionated heparin	1	81	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.13 [0.00, 6.65]
2.4 Enoxaparin versus unfractionated heparin	4	1934	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.79 [0.51, 1.22]
2.5 Reviparin versus unfractionated heparin	1	1020	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.08 [0.62, 1.89]
2.6 Certoparin versus unfractionated heparin	2	1469	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.73 [0.42, 1.25]
3 Incidence of recurrent venous thromboembolism at 3 months' follow‐up	11	5435	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.79 [0.60, 1.02]
3.1 Nadroparin versus unfractionated heparin	4	1436	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.73 [0.44, 1.22]
3.2 Tinzaparin versus unfractionated heparin	2	1044	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.54 [0.26, 1.08]
3.3 Enoxaparin versus unfractionated heparin	4	1934	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.79 [0.51, 1.22]
3.4 Reviparin versus unfractionated heparin	1	1021	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.09 [0.62, 1.90]
4 Reduction in thrombus size (pre‐ and post‐treatment venograms)	5	753	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.49 [0.37, 0.66]
4.1 Nadroparin versus unfractionated heparin	2	302	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.49 [0.31, 0.77]
4.2 Ardeparin versus unfractionated heparin	1	75	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.37 [0.14, 0.99]
4.3 Enoxparin versus unfractionated heparin	1	117	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.34 [0.17, 0.71]
4.4 Certoparin versus unfractionated heparin	1	259	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.63 [0.38, 1.04]
5 Incidence of major haemorrhagic episodes (during initial treatment)	12	6014	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.68 [0.45, 1.03]
5.1 Nadroparin versus unfractionated heparin	4	1436	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.51 [0.18, 1.40]
5.2 Tinzaparin versus unfractionated heparin	2	1044	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.30 [0.12, 0.73]
5.3 Enoxaparin versus unfractionated heparin	3	1034	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.14 [0.50, 2.61]
5.4 Reviparin versus unfractionated heparin	1	1021	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.26 [0.49, 3.19]
5.5 Certoparin versus unfractionated heparin	2	1479	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.62 [0.24, 1.56]
6 Overall mortality at the end of follow‐up	14	6984	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.80 [0.65, 0.99]
6.1 Nadroparin versus unfractionated heparin	4	1436	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.76 [0.47, 1.22]
6.2 Tinzaparin versus unfractionated heparin	2	1044	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.63 [0.37, 1.08]
6.3 Ardeparin versus unfractionated heparin	1	80	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
6.4 Enoxaparin versus unfractionated heparin	4	1934	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.90 [0.63, 1.29]
6.5 Reviparin versus unfractionated heparin	1	1021	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.92 [0.57, 1.47]
6.6 Certoparin versus unfractionated heparin	2	1469	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.70 [0.38, 1.26]