Study	Participants and indications	Demographics	Prediction of major bleeding by risk group
Beyth, 1998 (n = 820)1	Patients discharged on warfarin therapy (VTE, 47%; cardiac surgery, 18%; other, 35%)	Mean age = 60 years; 53% women	One-year bleeding risk using OBRI:
				Low risk: 3%
				Intermediate risk: 12%
				High risk: 48%
Kuijer, 1999 (n = 1,021)4	Patients discharged on warfarin therapy after diagnosis of VTE	Mean age = 61 years; 51% men	90-day bleeding risk:
				Low risk: 1%
				High risk: 7%
Wells, 2003 (n = 222)2	Pulmonary embolism or deep venous thrombosis; started on low-molecular-weight heparin as outpatients and then switched to warfarin	Mean age = 58 years; 43% women	Bleeding risk per person-year using OBRI:
				Low risk: 0%
				Intermediate risk: 4.3%
				High risk: not applicable*
Aspinall, 2005 (n = 1,269)3	Patients treated with warfarin at a Veterans Affairs anticoagulation clinic	Mean age = 68 years; 92% men	Bleeding risk per person-year using OBRI:
				Low risk: 0.8%
				Intermediate risk: 2.5%
				High risk: 10.6%
Shireman, 2006 (n = 26,345)5	Registry of patients hospitalized with atrial fibrillation and discharged on warfarin therapy	All 65 years or older (88% 70 years or older); 53% women	90-day bleeding risk
				Shireman rule:
					Low risk: 0.9%
					Intermediate risk: 2.0%
					High risk: 5.4%
					Intermediate- plus high-risk: 2.3%
				OBRI†:
					Intermediate risk: 1.0%
					High risk: 2.5%
				Kuijer rule:
					Intermediate risk: 1.5%
					High risk: 1.8%