The cumulative incidence of recurrent venous thromboembolism at 5 years was 22% after a first VTE and 28% after a second.
Risk factors associated with a higher rate of recurrent deep vein thrombosis:
(1) proximal extension of the deep vein thrombosis
(2) presence of cancer
(3) short duration of anticoagulation therapy (<= 6 months)
(4) history of a previous thromboembolic event
Factors associated with a lower rate of recurrent deep vein thrombosis:
(1) thrombosis occurring after surgery
(2) longer duration of anticoagulation therapy (> 12 months)
Limitations:
• The method acknowledges a history of previous deep vein thrombosis, but the risk of recurrence would seem to be higher if there have been multiple previous episodes.
• The model does not include mention of a hereditary hypercoagulable state which would benefit from lifelong prophylaxis.
