Calculators · Cardiology · Score

ORBIT bleeding score

Also called ORBIT-AF bleeding score, ORBIT score

Major bleeding risk in atrial fibrillation patients on oral anticoagulation.

ORBIT

0/7

Risk
Low (0–2)

Low (0–2): 2.4 major bleeds per 100 patient-years in the ORBIT-AF registry (patients on oral anticoagulants).

Formula and scoring

Older age ≥75 1, Reduced Hb/Hct or anaemia 2, Bleeding history 2, Insufficient kidney function (eGFR <60) 1, Treatment with antiplatelet 1. Low 0–2, medium 3, high ≥4.

Exam and ward pearls

  • ORBIT was better calibrated than HAS-BLED and ATRIA when tested in ROCKET-AF.

When not to rely on it

  • Derived in a US registry (ORBIT-AF, n = 7,411 on OAC).
  • The published table prints Hb thresholds as "mg/dL"; the values are g/dL.

Source

  1. O'Brien EC, Simon DN, Thomas LE, et al. The ORBIT bleeding score: a simple bedside score to assess bleeding risk in atrial fibrillation. Eur Heart J. 2015;36(46):3258-64. doi:10.1093/eurheartj/ehv476 · PMID 26424865

Formula and cut-offs checked against these sources on 8 Nov 2026. Educational tool for clinicians; it does not replace clinical judgement.

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