Table 1.

Calculation of the HAS-BLED and OBRI risk scores. All risk factors are scored as 1 point each unless otherwise noted. Because the HASBLED risk score was derived in patients on anticoagulation therapy, and because no patient in warfarin received both aspirin and warfarin concurrently, aspirin use in the HAS-BLED score was coded as 0 in this analysis. Similarly, for patients assigned to aspirin, the item for labile INR in the HAS-BLED score was coded as 0 for these patients. For abnormal liver function, based on available data in WARCEF, a cut-off for AST level of >114 IU/L was used.

HAS-BLED Risk Score	OBRI Risk Score
Hypertension (SBP >160 mmHg)	Age >65 years
Abnormal renal/ liver function (1 point for each)	History of stroke
Stroke	History of GIB
Bleeding	Recent MI, HCT <30%, Cr >1.5 mg/dL, or diabetes mellitus
Labile INRs (TTR <60%)
Elderly (age >65 years)
Drugs (antiplatelet agents / NSAIDs) or excess alcohol (1 point for each)

Abbreviations: SBP, systolic blood pressure; TTR, time in therapeutic range; NSAID, non-steroidal anti-inflammatory drugs; GIB, gastrointestinal tract bleeding; MI, myocardial infarction; HCT, hematocrit; Cr, creatinine.