The ORBIT bleeding risk score evaluates the likelihood of bleeding in individuals with atrial fibrillation through a straightforward assessment of five patient factors. Each factor's presence contributes to the overall score, helping clinicians estimate the potential bleeding risk.

Here's how the score is computed:

1. Age greater than 74 years: 
   - Assign 1 point for "Yes", 0 points for "No".

2. Presence of reduced hemoglobin/hematocrit or anemia:
   - Assign 2 points for "Yes", 0 points for "No".

3. History of bleeding:
   - Assign 2 points for "Yes", 0 points for "No".

4. Glomerular filtration rate (GFR) less than 60 mL/min/1.73 m²:
   - Assign 1 point for "Yes", 0 points for "No".

5. Treatment with antiplatelet agents:
   - Assign 1 point for "Yes", 0 points for "No".

Total the points from all of these inputs to get a score ranging from 0 to 7. This overall score provides an interpretation of the patient's bleeding risk:

- Scores from 0 to 2 suggest a bleeding risk of approximately 2.4%.
- A score precisely at 3 indicates a bleeding risk of roughly 4.7%.
- Scores ranging from 4 to 7 reflect an elevated bleeding risk of about 8.1%.

This systematic approach allows healthcare providers to assess and communicate bleeding risks effectively, enabling informed decision-making for managing atrial fibrillation.

The ORBIT (Outcomes Registry for Better Informed Treatment) bleeding risk score is a clinical calculator specifically designed for patients with atrial fibrillation. This scoring system is used to predict the risk of major bleeding in patients with atrial fibrillation who are receiving anticoagulant therapy. The ORBIT score includes five variables: age, anemia, severe renal disease, prior bleeding, and treatment with antiplatelet agents. The score ranges from 0 to 7, with higher scores indicating a higher risk of bleeding. This tool is particularly useful in guiding clinicians in their decision-making process regarding the initiation or continuation of anticoagulant therapy in patients with atrial fibrillation. It should not be used in patients without atrial fibrillation or those not receiving anticoagulant therapy, as it has not been validated in these populations.

ORBIT bleeding risk score in atrial fibrillation