Optimal duration of oral anticoagulant therapy in venous thromboembolism.

Recent trials with sufficient statistical power have demonstrated that the duration of oral anticoagulation in many cases need to be extended well beyond 4-6 weeks. Since many individual factors, as risk of hemorrhage and of recurrence, compliance and cost have to be weighed into a decision, it is difficult to issue general recommendations. Several of these factors, especially those influencing the risk of recurrent event are reviewed here. The ideal solutions will perhaps only be achieved when we have learned how to combine the optimal duration with a time-adjusted decrease in oral anticoagulation.