What is the Glasgow-Blatchford Score (GBS) Used For?
The Glasgow-Blatchford Score (GBS) is used to identify patients with upper gastrointestinal bleeding who are at low risk for adverse outcomes and can be safely managed as outpatients without hospitalization or urgent endoscopy. 1, 2
Primary Clinical Purpose
The GBS serves as a pre-endoscopy risk stratification tool that uses only clinical and laboratory data available at initial presentation—no endoscopy required. 3, 1 This distinguishes it from other scoring systems like the complete Rockall score, which requires endoscopic findings. 3
What the GBS Predicts
The score identifies patients who:
- Will NOT require hospital-based intervention (endoscopic therapy, surgery, radiologic intervention, or blood transfusion) 3, 1
- Are at very low risk for rebleeding within 30 days 2, 4
- Are at very low risk for mortality 3, 5
Score Components
The GBS incorporates six clinical and laboratory parameters: 3, 1
- Hemoglobin level
- Blood urea nitrogen (BUN) level
- Systolic blood pressure
- Pulse rate
- Presence of melena
- Presence of syncope
- Evidence of hepatic disease
- Evidence of cardiac failure
Critical Threshold for Safe Discharge
A GBS score of ≤1 identifies patients at very low risk who can be safely managed as outpatients without early endoscopy. 1, 2 At this threshold:
- Sensitivity is 98.6-99% for detecting high-risk patients, meaning it misclassifies ≤1% of high-risk patients as low risk 3, 1
- Negative predictive value is 96.3-96.6% for safe discharge 6, 4
Why GBS is Preferred Over Other Scores
The American College of Physicians and European Society of Gastrointestinal Endoscopy recommend GBS as the preferred prognostic tool over alternatives like the Rockall score or AIMS65. 3, 1, 2 Here's why:
Compared to Pre-endoscopic Rockall Score:
- GBS has superior sensitivity (99% vs 93-96%) for identifying high-risk patients 3, 1
- The Rockall score may misclassify 4-7% of high-risk patients as low risk 3, 1
- Rockall is better for predicting mortality specifically, but worse for identifying who needs intervention 3
Compared to AIMS65:
- AIMS65 has much lower sensitivity (78-82%) and may misclassify approximately 20% of high-risk patients as low risk 3, 1
- AIMS65 was designed to identify high-risk patients for death, not to identify low-risk patients for safe discharge 3, 1
Clinical Implementation
Use GBS at initial presentation in the emergency department before endoscopy to make triage decisions. 2 Patients with GBS ≤1 can be:
- Discharged home with outpatient endoscopy follow-up 2
- Spared unnecessary hospitalization and its associated costs 3
- Managed without urgent intervention 1
Important Caveats:
Consider additional factors when deciding on early discharge: 1
- Urban versus rural environment and access to emergency services
- Availability of out-of-hours endoscopy
- Patient preferences (some may prefer diagnostic certainty over early discharge)
- Social support and ability to return if symptoms worsen
Performance Across Different Outcomes
The GBS demonstrates excellent predictive accuracy for: 5, 4
- Mortality: AUROC 0.90 (cutoff 12.5, sensitivity 82%, specificity 100%) 5
- Blood transfusion need: AUROC 0.75-0.78 (cutoff 9.5, sensitivity 69%, specificity 79%) 5, 4
- Composite adverse outcomes: AUROC 0.77-0.78 4
The GBS performs comparably in lower gastrointestinal bleeding (AUROC 0.78), though it was originally developed for upper GI bleeding. 7
Practical Advantage
The GBS can be calculated immediately upon patient arrival using vital signs and routine laboratory tests, without waiting for endoscopy. 3 This allows for rapid decision-making about disposition and resource allocation, unlike the complete Rockall score which requires endoscopic findings. 3