What is the National Early Warning Score 2 (NEWS2) and how is it calculated?

What is NEWS2 Score

NEWS2 (National Early Warning Score 2) is a standardized physiological scoring system that calculates aggregate risk of severe illness or death by measuring six vital parameters, with scores ranging from 0 (very low risk) to potentially >20, where higher scores directly correlate with mortality and need for escalation of care. 1

How NEWS2 is Calculated

NEWS2 uses six physiological measurements, each assigned points based on deviation from normal values 1:

The Six Parameters:

1. Respiratory rate (per minute)

   • 3 points: <8 or ≥25
   • 2 points: 21-24
   • 1 point: 9-11
   • 0 points: 12-20

2. Oxygen saturation (two scales available)

   • Scale 1 (standard): 3 points for <91%, decreasing to 0 points for ≥96%
   • Scale 2 (for hypercapnic respiratory failure): Adjusts target saturations to 88-92%

3. Supplemental oxygen

   • 2 points: If receiving oxygen
   • 0 points: Breathing room air

4. Systolic blood pressure (mm Hg)

   • 3 points: <90 or ≥220
   • 2 points: 91-100
   • 1 point: 101-110
   • 0 points: 111-219

5. Heart rate/Pulse (per minute)

   • 3 points: <40 or ≥131
   • 1 point: 41-50 or 91-110
   • 2 points: 111-130
   • 0 points: 51-90

6. Level of consciousness

   • 3 points: Any alteration (CVPU = Confusion/new, Voice response, Pain response, Unresponsive)
   • 0 points: Alert

7. Temperature (°C)

   • 3 points: <35.0
   • 2 points: ≥39.1
   • 1 point: 35.1-36.0 or 38.1-39.0
   • 0 points: 36.1-38.0

Risk Stratification

The aggregate score determines risk level 1:

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

Critical Single Parameter Rule

A score of 3 in ANY single parameter automatically indicates increased risk, regardless of total score 1. This is based on Royal College of Physicians consensus and clinical experience.

Clinical Application and Monitoring Frequency

Based on 2024 NICE guidance, monitoring frequency should be adjusted to risk level 1:

• High risk (≥7): Re-calculate every 30 minutes
• Moderate risk (5-6): Re-calculate every hour
• Low risk (1-4): Re-calculate every 4-6 hours
• Very low risk (0): Follow standard protocol

Important Clinical Caveats

Context Matters

Always interpret NEWS2 in the context of underlying physiology and comorbidities 1. The score may underestimate risk in patients with:

• Chronic conditions affecting baseline vital signs
• Deteriorating trends despite stable scores
• Clinical red flags (mottled/ashen appearance, non-blanching rash, cyanosis)

When NEWS2 May Mislead

Recent research shows NEWS2 has limitations in predicting time-critical interventions, with sensitivity of only 51.8% for identifying patients needing urgent treatment 2. Specifically, 37 of 45 patients requiring emergency surgery, antibiotics for open fractures, or limb-threatening injury management had NEWS2 ≤4 2.

Patients frequently score maximum points for respiratory rate, altered consciousness, or supplemental oxygen use without actually needing time-critical intervention 2, potentially leading to over-triage.

Primary Purpose

NEWS2 was developed by the Royal College of Physicians and endorsed by NHS England specifically for stratifying risk of severe illness or death from sepsis and guiding antibiotic timing 1. It is used in acute hospital, mental health, and ambulance settings 1.

The system aims to standardize early recognition of patient deterioration nationally, with the understanding that failing to recognize clinical deterioration promptly can be life-threatening 1.