Table I. Inclusion and exclusion criteria for COAG trial.

Inclusion Criteria

Age ≥18 y Willingness and ability to sign informed consent Able to be followed in outpatient anticoagulation clinic Expected duration of warfarin therapy of at least 1 m Anticoagulation management for the patient will be performed in-hospital and as an outpatient by clinicians that will adhere to the study dosing algorithms and dose titration plans Target INR 2-3

Exclusion Criteria

Currently taking warfarin Prior warfarin therapy with known required stable dose Clinician opinion that warfarin dosing needs to be adjusted for reasons not accounted for by dosing algorithm Abnormal baseline INR (off warfarin), eg, due to liver disease, antiphospholipid antibody Contraindication to warfarin treatment for at least 3 months Life expectancy <1 y Pregnant women or childbearing women not using medically approved method of birth control Inability to follow-up on a regular basis with anticoagulation practitioners participating in trial Any factors likely to limit adherence to warfarin (eg, dementia, alcohol or substance abuse, plans to move in the next 6 m, history of unreliability in medication taking or appointment keeping, significant concerns about participation in the study from spouse, significant other, or family members, lack of support from primary health care provider) Cognitive or other causes of inability to provide informed consent or follow study procedures Participating in another trial that prohibits participation in the COAG trial or planned enrollment in such a trial within the first 6 m of warfarin therapy Estimated blood loss of >1000 mL requiring blood transfusions within 48 h before randomization Genotype (CYP2C9 or VKORC1) known to participant from prior testing

Abbreviations: CYP2C9, Cytochrome P450 2C9; VKORC1, vitamin K epoxide reductase complex subunit 1.