Venous thromboembolism prophylaxis for medical service-mostly cancer-patients at hospital discharge.

OBJECTIVE: Many hospitalized Medical Service patients remain at high risk for venous thromboembolism (VTE) after hospital discharge. Our aim was to compare the effect of the use or omission of extended pharmacologic VTE prophylaxis after hospital discharge among Medical Service patients on the incidence of symptomatic deep vein thrombosis (DVT) or pulmonary embolism (PE) over the ensuing 3 months.

METHODS: In this case-control study, we identified a case population of 461 patients for whom parenteral pharmacological VTE prophylaxis was prescribed to continue after discharge and matched them according to age, sex, and VTE risk score to a control group of 922 patients for whom VTE prophylaxis was not continued after discharge.

RESULTS: The primary endpoint of symptomatic DVT or PE at 90 days occurred in 5.0% of patients receiving extended prophylaxis compared with 4.3% of patients who received no prophylaxis after discharge (P=.58). Fewer patients were alive at 90 days in patients receiving extended pharmacologic VTE prophylaxis, compared with those who received no prophylaxis after discharge (56.8% vs 68.4%, P <.001). Major bleeding, defined as those events requiring blood transfusion, medical, or surgical intervention, occurred more frequently in patients receiving extended VTE prophylaxis after discharge than in those patients who received no prophylaxis after discharge (3.9% vs 1.9%, P=.03).

CONCLUSION: Extended pharmacologic thromboprophylaxis in high-risk Medical Service patients did not reduce symptomatic DVT and PE in the ensuing 90 days after hospital discharge. There was a higher incidence of all-cause death and major bleeding episodes in patients receiving extended prophylaxis. Our observations do not support the routine use of extended VTE prophylaxis in Medical Service patients. Further research is needed to identify patients who may benefit from extended pharmacologic VTE prophylaxis and those who may have too great a bleeding risk.