Deep venous thrombosis: a continuing problem.

The incidence of deep vein thrombosis after major operations in patients over the age of 40 approaches 30% if no prophylactic measures are used.' Many patients discharged from hospital are still at risk at home and the question arises whether prophylaxis should be continued after patients have been discharged. To try to answer this question we followed up patients, most of whom received prophylaxis for deep vein thrombosis during their stay in hospital, for up to six weeks after their discharge from hospital.