Prevention

High-risk cases

Alternatives include warfarin  ^{a b}

Why?

• Warfarin reduces venous thromboembolism in patients having elective total hip replacement  ^{a b} or with metastatic breast carcinoma receiving chemotherapy. ^a
• Pneumatic compression or LMWH are more effective than warfarin at reducing symptomatic DVT following total knee arthroplasty. ^a
• LMWH and warfarin are equally cost-effective in preventing DVT in patients undergoing total hip or knee replacement. The final decision depends on local drug costs, and the costs of monitoring warfarin therapy and treating bleeds. ^a

Warfarin reduces venous thromboembolism but is less effective than LMWH or pneumatic compression

Patient	Treatment	Comparison	Outcome	CER	OR (95% CI)	NNT (95% CI)
elective total hip replacement a	warfarin	placebo or nothing	venous thromboembolism at discharge	?	0.24 (0.13 to 0.34)	4 (3 to 8)
total knee arthroplasty a	LMWH	warfarin	symptomatic DVT  at days	45%	1.9 (1.6 to 2.3)	6 (5 to 9)
	pneumatic compression	warfarin		45%	2.05 (1.76 to 2.39)	6 (5 to 7)
cancer patients having chemotherapy a	warfarin	placebo	DVT at 19 days	4.3%	100	23 (14 to 85)