Which bedside sepsis risk score (quick Sequential Organ Failure Assessment (qSOFA) or Sequential Organ Failure Assessment (SOFA)) should I use to decide if a patient with suspected infection needs urgent escalation?

Sepsis Risk Stratification: Which Score to Use

Use NEWS2 (National Early Warning Score 2) rather than qSOFA or SOFA for initial bedside risk stratification in patients with suspected infection requiring urgent escalation decisions. 1, 2

Why NEWS2 Over qSOFA or SOFA

The 2024 NICE guidelines have definitively moved away from qSOFA as the primary screening tool, instead adopting NEWS2 as the standard for identifying sepsis risk in emergency and acute care settings. 1 This represents a significant shift from the 2016 Sepsis-3 definitions that introduced qSOFA. 3

Key Evidence Supporting NEWS2

• Superior sensitivity: NEWS2 demonstrates significantly better discrimination for in-hospital mortality (AUC 0.77) compared to qSOFA (AUC 0.69) and outperforms qSOFA in predicting ICU transfer and death. 4

• Earlier detection: While qSOFA identifies high-risk patients only 5 hours before clinical deterioration, NEWS2 captures at-risk patients 17 hours earlier, allowing more time for intervention. 4

• Better sensitivity-specificity balance: NEWS2 achieves 67% sensitivity and 66% specificity for the composite outcome of death or ICU transfer, compared to qSOFA's 54% sensitivity and 67% specificity. 4

The NEWS2 Risk Stratification Algorithm

Step 1: Calculate NEWS2 Score

NEWS2 assesses six physiological parameters, each scored 0-3 points: 1, 2

• Respiratory rate
• Oxygen saturation (with adjustment for hypercapnic respiratory failure)
• Supplemental oxygen requirement
• Systolic blood pressure
• Heart rate
• Level of consciousness (Alert vs CVPU)
• Temperature

Step 2: Interpret Risk Categories

• Score ≥7: High risk of severe illness or death from sepsis 1, 2
• Score 5-6: Moderate risk 1, 2
• Score 1-4: Low risk 1, 2
• Score 0: Very low risk 1, 2

Step 3: Override Criteria (Upgrade Risk Regardless of Score)

Immediately escalate if ANY of these are present: 1, 2

• Mottled or ashen appearance
• Non-blanching petechial or purpuric rash
• Cyanosis of skin, lips, or tongue
• Single parameter scoring 3 points (indicates increased risk even with low total score) 1, 2

Step 4: Contextual Interpretation

Adjust your assessment if: 1, 2

• Patient's condition is deteriorating despite interventions
• Baseline physiology or comorbidities suggest higher vulnerability
• Previous NEWS2 scores show worsening trend

Urgent Escalation Timing Based on NEWS2

High Risk (NEWS2 ≥7)

• Re-assess: Every 30 minutes 1, 2
• Antibiotics: Within 1 hour 1, 2
• Action: Immediate senior clinician review, consider ICU-level care 2

Moderate Risk (NEWS2 5-6)

• Re-assess: Every hour 1, 2
• Antibiotics: Within 3 hours 1, 2
• Action: Escalate to experienced clinician (FY2 level or above) 1

Low Risk (NEWS2 1-4)

• Re-assess: Every 4-6 hours 1, 2
• Antibiotics: Within 6 hours 1, 2

When to Use SOFA Instead

Reserve full SOFA score calculation for patients already identified as high-risk by NEWS2 or those in ICU settings. 2, 5 SOFA is the definitive diagnostic tool for sepsis (requiring ≥2 point increase from baseline), but it requires laboratory values and is too complex for rapid bedside screening. 1, 3

The full SOFA score assesses: 2, 5

• Respiratory function (PaO2/FiO2 ratio)
• Cardiovascular function (MAP and vasopressor requirements)
• Hepatic function (bilirubin)
• Coagulation (platelet count)
• Renal function (creatinine and urine output)
• Neurological function (Glasgow Coma Scale)

Why qSOFA Is Insufficient for Screening

qSOFA should NOT be used as the sole screening tool for sepsis. 4, 6 Despite being introduced in Sepsis-3 guidelines, subsequent research has revealed critical limitations:

• Low sensitivity: qSOFA misses 46% of patients who die or require ICU transfer 4
• Delayed identification: Identifies patients too late in their clinical course 4
• Poor discrimination: Lower predictive accuracy than NEWS2 and other early warning scores 4, 6

The 2021 Surviving Sepsis Campaign Guidelines explicitly discourage relying solely on qSOFA and recommend additional tools. 7

Common Pitfalls to Avoid

1. Don't wait for qSOFA ≥2 before escalating: This misses too many high-risk patients and delays intervention. 4

2. Don't ignore single abnormal parameters: A NEWS2 score of 3 in any single parameter warrants concern even if total score is low. 1, 2

3. Don't apply NEWS2 mechanistically: Always interpret scores in context of baseline physiology, comorbidities, and clinical trajectory. 1, 2

4. Don't delay antibiotics to calculate complex scores: In obviously sick patients, initiate treatment while completing assessment. 1

5. Don't use NEWS2 in specialized populations without caution: Patients with spinal injury, chronic heart/lung disease may have altered baseline physiology that affects score accuracy. 1

Practical Implementation

For emergency department triage: Calculate NEWS2 immediately upon suspicion of infection, then use the risk category to determine monitoring frequency and antibiotic timing. 1

For ward patients: Implement serial NEWS2 monitoring at intervals determined by risk category, escalating if scores worsen or fail to improve with treatment. 1, 2

For ICU consideration: NEWS2 ≥7 or consecutive scores ≥5 should trigger alert to hospital for potential ICU-level care needs. 1