Table 2.

Clinical trials assessing prophylaxis of VTE in hospitalized medical patients

Clinical trial	Number of patients	Cancer patients (%)	Study drugs	VTE events	Relative risk reduction	Major bleeding	NTT	Cancer subgroup VTE events
ARTEMIS	849	15.4	Fondaparinux sc (2.5 mg/24 h) vs. placebo	5.6 vs. 10.5 % p = 0.029	0.47	0.2 vs. 0.2 % p = NS	20	17.0 vs. 3.9 % RR 4.3 NNH 8
MEDENOX	866	12.4	Enoxaparin sc (40 mg/24 h) vs. placebo	5.5 vs. 14.9 % p < 0.001	0.37	1.7 vs. 1.1 % p = NS	11	9.7 vs. 19.5 % RR 0.50 (95 % CI 0.14–1.72) NNT 10
PREVENT	3,706	5.1	Dalteparin sc (5,000 UI/24 h) vs. placebo	2.8 vs. 5.0 % p = 0.0015	0.55	0.5 vs. 0.2 % p = NS	45	3.1 vs. 8.3 % RR 0.37 NNT 18

sc subcutaneously, VTE venous thromboembolism, NS not significant, NTT number of patients needed to treat to avoid one event, NNH number needed to harm, RR relative risk, CI confidence interval