What is the ORBIT score?
ORBIT estimates the risk of major bleeding in people with atrial fibrillation on anticoagulation. It uses five simple items.
NICE NG196 (2021) recommends ORBIT to assess bleeding risk. It replaced HAS-BLED in NICE guidance because it predicts bleeding better.
ORBIT criteria and points
| Letter | Criterion | Points |
|---|---|---|
| O | Older age: over 74 | 1 |
| R | Reduced Hb or anaemia history | 2 |
| B | Bleeding history | 2 |
| I | Insufficient kidney function: eGFR below 60 | 1 |
| T | Treatment with antiplatelets | 1 |
ORBIT score interpretation
| Score | Bleeding risk |
|---|---|
| 0–2 | Low |
| 3 | Medium |
| 4–7 | High |
ORBIT vs HAS-BLED
Both estimate bleeding risk on anticoagulation. NICE now prefers ORBIT. It was better calibrated in validation studies and is simpler to complete.
A high score is not, on its own, a reason to withhold anticoagulation. Use it to find and fix modifiable risks.
Modifiable bleeding risks to review
- Uncontrolled blood pressure
- Antiplatelets and NSAIDs
- Excess alcohol
- Anaemia
- Labile INR on warfarin
- Wrong DOAC dose for renal function