Follow-up

• high therapeutic range  ^b
• supratherapeutic INR ( > 4.5)  ^{a b}
• recently started warfarin  ^a
• old age  ^a
• arterial disease  ^a
• co-morbid conditions  ^b (stroke, serious heart, liver or renal disease) 
• previous GI bleed  ^a
• on NSAIDs   ^b

Why?

High anticoagulation and recent onset of warfarin increase the risk of major bleeding

Patient	Prognostic Factor	Outcome	CER	RR (95% CI)	NNF+ (95% CI)
elderly on anticoagulation b	INR range 3.0 - 4.0 independent	severe bleed at 2-3 years	9.8%	1.55 (1.17 to 2.06)	19 (10 to 63)
anticoagulation a	INR > 4.5 independent	major bleed at 9 months	1.0%	5.96 (3.68 to 9.67)	20 (11 to 37)
	< 90 days since commencing therapy independent	major bleed at 9 months	1.0%	2.5 (1.4 to 3.3)	65 (43 to 250)
	aged 70 or more independent	major bleed at 9 months	0.7%	1.69 (1.21 to 2.37)	140 (72 to 470)
	arterial disease requiring anticoagulation independent	major bleed at 9 months	1.0%	1.72 (1.17 to 2.54)	140 (64 to 580)