EXCLAIM:Extended Prophylaxis for Venous ThromboEmbolism (VTE) in Acutely Ill Medical Patients With Prolonged Immobilization

Primary objective: * To demonstrate the superiority of extended VTE prophylaxis with enoxaparin 40mg sc qd for 28 ± 4 days, compared to placebo, both following 10 ± 4 days of initial treatment with enoxaparin 40mg sc qd Secondary objectives: * To assess the reduction in mortality rate at the end of the double-blind treatment period, at 3 (90 ± 10 days) and at 6 (180 ± 10 days) months from the time of entry to the study, in patients on extended prophylaxis * To assess the incidence of VTE at 3 months (90 ± 10 days) from the time of randomization to the study * To evaluate the safety of extended enoxaparin VTE prophylaxis in acutely ill medical patients with prolonged immobilization. Safety evaluation includes: * Major and minor hemorrhage * Heparin induced thrombocytopenia * Serious adverse events * To assess differences in levels of health-care utilization and cost between patients receiving extended VTE prophylaxis versus those receiving placebo.