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ORBIT Bleeding Risk Score for Atrial Fibrillation

The ORBIT score (0–7) predicts major bleeding in AF patients on anticoagulation: 0–2 low (2.4 bleeds/100 patient-years), 3 medium (4.7), 4–7 high (8.1). Items: older age, reduced hemoglobin/anemia, bleeding history, insufficient kidney function, antiplatelet use.

Age (years)
Reduced Hb (< 13 g/dL men, < 12 women), Hct (< 40% men, < 36% women) or history of anemia (yes/no, +2)
Bleeding history (GI, intracranial or hemorrhagic stroke) (yes/no, +2)
Insufficient kidney function (eGFR < 60) (yes/no, +1)
Treatment with antiplatelet (yes/no, +1)

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Interpretation

Result	Meaning
0–2	Low (2.4 bleeds/100 pt-yr)
3	Medium (4.7)
4–7	High (8.1)

Formula

O: older (≥ 75) 1 · R: reduced Hb/Hct or anemia history 2 · B: bleeding history 2 · I: insufficient kidney function (eGFR < 60) 1 · T: treatment with antiplatelet 1

Clinical pearls

ORBIT performed at least as well as HAS-BLED for predicting major bleeding and uses routinely available data.
Like HAS-BLED, a high score should prompt attention to modifiable factors rather than withholding anticoagulation.

Examples

orbit score 78F with anemia on aspirin orbit bleeding risk 70M prior gi bleed egfr 45 af bleeding risk orbit for 80 year old man, no anemia, no bleeding history

FAQ

What does ORBIT stand for?

Older age (≥75), Reduced hemoglobin/hematocrit or anemia, Bleeding history, Insufficient kidney function (eGFR <60), and Treatment with antiplatelets.

ORBIT or HAS-BLED?

Both are acceptable; ORBIT is simpler to complete from labs, while HAS-BLED highlights more modifiable risk factors.

Evidence

O'Brien EC et al. The ORBIT bleeding score: a simple bedside score to assess bleeding risk in atrial fibrillation. Eur Heart J 2015;36:3258–64.

Cardiology · Reviewed 2026-10-14 · Methodology