Therapy

Why?

• Complications are common. Calf DVTs can propagate (6% to 23%), and lead to recurrent DVT (4% to 9%) or chronic venous insufficiency (21% to 79%) ^c
• Anticoagulation reduces recurrent venous thromboembolism. Patients with calf DVT who are anticoagulated with heparin followed by warfarin for 3 months are less likely to have recurrences than patients just given heparin for 5 days. ^a

Anticoagulation reduces recurrent venous thromboembolism in patients with a calf DVT

Patient	Treatment	Comparison	Outcome	CER	RRR (95% CI)	NNT (95% CI)
calf DVT a	heparin for 5 days and warfarin for 3 months	heparin for 5 days	recurrence of venous thromboembolism at 12 months	32%	87% (27% to 100%)	4 (2 to 12)