The mean relative risk reduction for LMWH prophylaxis for deep vein thrombosis was 0.48 versus placebo, 0.31 versus low dose UFH and 0.53 versus dextran 70. The mean relative risk reduction for LMWH prophylaxis for pulmonary embolism was 0.50, 0.67 and -0.50 versus placebo, low dose UFH and dextran 70, respectively. The mean relative risk reduction for LMWH prophylaxis for major bleeding complications was 0 versus placebo, 0.39 versus low dose UFH and 0.67 versus dextran 70. The mean relative risk reduction for LMWH prophylaxis for blood transfusions was -0 .08, 0.14and 0.19 versus placebo, low dose UFH and dextran 70, respectively.