What is the clinical significance and management approach of the Oakland score?

The Oakland Score: Clinical Significance and Management Approach

The Oakland score is a validated risk assessment tool that stratifies patients with lower gastrointestinal bleeding (LGIB) as having major or minor bleeds, with scores ≤8 indicating patients who can be safely discharged for outpatient investigation, while scores >8 classify patients as having major bleeds requiring hospital admission. 1

Components and Calculation

The Oakland score is calculated using seven variables:

• Age:

  • <40 years: 0 points
  • 40-69 years: 1 point
  • ≥70 years: 2 points 1

• Gender:

  • Female: 0 points
  • Male: 1 point 1

• Previous LGIB admission:

  • No: 0 points
  • Yes: 1 point 1

• Digital Rectal Examination findings:

  • No blood: 0 points
  • Blood: 1 point 1

• Heart rate:

  • <70 bpm: 0 points
  • 70-89 bpm: 1 point
  • 90-109 bpm: 2 points
  • ≥110 bpm: 3 points 1

• Systolic blood pressure:

  • <90 mmHg: 5 points
  • 90-119 mmHg: 4 points
  • 120-129 mmHg: 3 points
  • 130-159 mmHg: 2 points
  • ≥160 mmHg: 0 points 1

• Hemoglobin (g/L):

  • <70 g/L: 22 points
  • 70-89 g/L: 17 points
  • 90-109 g/L: 13 points
  • 110-129 g/L: 8 points
  • 130-159 g/L: 4 points
  • ≥160 g/L: 0 points 1

Total scores range from 0 to 35 points, with higher scores indicating greater risk 2.

Clinical Significance

Risk Stratification

• The Oakland score helps categorize patients with LGIB into risk groups:

  • Score ≤8: Minor, self-terminating bleed - safe for discharge and outpatient investigation 1
  • Score >8: Major bleed - requires hospital admission 1

• The score has excellent discriminatory capacity with area under the receiver operating characteristic (AUROC) curve of 0.83-0.85 in validation studies 2, 3

Predicting Adverse Outcomes

The Oakland score predicts the risk of 30-day adverse events, defined as:

• Rebleeding (additional blood transfusion requirements and/or further decrease in hematocrit ≥20% after 24 hours of clinical stability)
• Red blood cell transfusion
• Therapeutic intervention to control bleeding (surgery, mesenteric embolization, or endoscopic hemostasis)
• In-hospital death (all cause)
• Readmission with further LGIB within 28 days 2

Management Approach Based on Oakland Score

Initial Assessment

• All patients presenting with LGIB should first be assessed for hemodynamic stability using shock index (heart rate/systolic BP) 1
• Patients with shock index >1 are classified as unstable and require immediate resuscitation and investigation 1
• For hemodynamically stable patients, calculate the Oakland score to determine management 1

Management Algorithm

1. For patients with Oakland score ≤8 (minor bleed):

   • Safe for discharge from the emergency department 1
   • Arrange urgent outpatient investigation (colonoscopy) 1
   • For patients over 50 with unexplained rectal bleeding, endoscopy within 2 weeks is recommended due to 6% risk of underlying bowel cancer 1
   • Assessment of anal canal and rectum should be performed using rigid sigmoidoscopy, proctoscopy, or flexible endoscopic examination 1

2. For patients with Oakland score >8 (major bleed):

   • Hospital admission is recommended 1
   • Colonoscopy on the next available inpatient list 1
   • If hemodynamically unstable (shock index >1) or active bleeding is suspected:
     • CT angiography is recommended as the fastest means to localize bleeding 1
     • If no source identified on CT angiography, immediate upper endoscopy should be performed 1
     • If a bleeding source is identified on CT angiography, catheter angiography with embolization should be performed as soon as possible 1

3. For patients requiring blood transfusion:

   • Use restrictive red blood cell transfusion thresholds:
     • Hemoglobin trigger of 70 g/L and target of 70-90 g/L after transfusion
     • For patients with cardiovascular disease: trigger of 80 g/L and target of 100 g/L 1

Limitations and Considerations

• Although internally and externally validated, the Oakland score has not been extensively tested in populations outside the UK 1
• Some studies suggest that raising the threshold to 9 or 10 points might improve sensitivity without significantly compromising specificity 3, 4
• The score may underestimate the number of patients who can be safely discharged due to liberal use of RBC transfusion in the population used to derive the score 1
• Baseline anemia is not specifically accounted for in the Oakland score, which may affect its performance in certain populations 4
• Recent validation studies show excellent performance with AUROC of 0.84-0.85 in emergency department settings 2, 5

Cost-Effectiveness

• Early risk stratification using the Oakland score can reduce unnecessary hospital admissions 1
• Implementing the Oakland score may lead to cost savings by:
  • Reducing length of stay for low-risk patients
  • Avoiding unnecessary transfusions (which account for up to 80% of RBC transfusions in LGIB) 1
  • Focusing resources on high-risk patients who truly need hospital-based interventions 1