NEXUS Criteria Calculator

Determine if cervical spine imaging is required using the NEXUS 5-criteria low-risk assessment.

Important Clinical Disclaimer: NEXUS Criteria Calculator is intended for use by qualified healthcare professionals only. It is for educational and informational purposes and should not replace clinical judgement. Always interpret results alongside the full clinical picture and follow your local guidelines and protocols.
NEXUS Low-Risk Criteria

Patient can be cleared clinically (no imaging required) if ALL 5 low-risk criteria are present:

Absence of tenderness on palpation of the posterior midline cervical spine from nuchal ridge to T1.
No clinical evidence of alcohol or drug intoxication.
Patient is fully alert with GCS 15 and no altered level of consciousness.
Absence of any focal neurological signs or symptoms.
No injury that might distract the patient from perceiving neck pain.
About the NEXUS Criteria
Background

The NEXUS (National Emergency X-Radiography Utilization Study) criteria were developed from a prospective observational study of over 34,000 patients published in the New England Journal of Medicine in 2000. The study identified 5 clinical criteria that, when all present, effectively rule out clinically significant cervical spine injury.

The Five Low-Risk Criteria

All 5 criteria must be met to clear the cervical spine without imaging:

  1. No posterior midline cervical tenderness
  2. No evidence of intoxication
  3. Normal level of alertness
  4. No focal neurological deficit
  5. No painful distracting injury
Performance Characteristics
  • Sensitivity: 99.0% (95% CI: 98.0-99.6%)
  • Specificity: 12.9%
  • Negative Predictive Value: 99.8%
  • 8 injuries missed in 818 patients with injury (0.98%)
Comparison with Canadian C-Spine Rule

A direct comparison study (Stiell et al., NEJM 2003) found the Canadian C-Spine Rule had higher sensitivity (99.4% vs 90.7% in that study) and higher specificity (45.1% vs 36.8%). However, NEXUS remains widely used due to its simplicity. Both are acceptable approaches per NICE guidelines.

Frequently Asked Questions

NEXUS (National Emergency X-Radiography Utilization Study) criteria are 5 clinical findings used to identify trauma patients at very low risk of cervical spine injury. If ALL 5 criteria are met (patient is low-risk for all), cervical spine imaging is not required.

The 5 NEXUS low-risk criteria are: (1) No posterior midline cervical tenderness, (2) No evidence of intoxication, (3) Normal level of alertness, (4) No focal neurological deficit, and (5) No painful distracting injury. ALL must be present to clear the c-spine without imaging.

The original NEXUS validation study showed 99.0% sensitivity and 12.9% specificity for detecting clinically significant cervical spine injuries. The negative predictive value is 99.8%. However, comparison studies suggest the Canadian C-Spine Rule may have slightly higher sensitivity and specificity.

Both are valid clinical decision rules. NEXUS is simpler with just 5 criteria and no stepped algorithm, making it faster to apply. The Canadian C-Spine Rule has slightly better performance metrics but is more complex. NICE guidelines support either approach for alert, stable adults after blunt trauma.
References
  1. Hoffman JR, Mower WR, Wolfson AB, et al. Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma. N Engl J Med. 2000;343(2):94-99. PMID: 10891516
  2. Stiell IG, Clement CM, McKnight RD, et al. The Canadian C-spine rule versus the NEXUS low-risk criteria in patients with trauma. N Engl J Med. 2003;349(26):2510-2518. PMID: 14695411
  3. NICE Guideline NG41. Spinal injury: assessment and initial management. National Institute for Health and Care Excellence. 2016 (updated 2023). NICE NG41
  4. Michaleff ZA, Maher CG, Verhagen AP, et al. Accuracy of the Canadian C-spine rule and NEXUS to screen for clinically important cervical spine injury in patients following blunt trauma: a systematic review. CMAJ. 2012;184(16):E867-E876. PMID: 23048086
NEXUS at a Glance

ALL 5 must be present to CLEAR:

  1. No midline tenderness
  2. No intoxication
  3. Normal alertness (GCS 15)
  4. No focal neurology
  5. No distracting injury

Any criterion ABSENT = IMAGE

Distracting Injuries

Examples that may mask neck pain:

  • Long bone fractures
  • Visceral injuries requiring surgery
  • Large lacerations or degloving
  • Crush injuries
  • Significant burns
  • Any severely painful injury
Performance
Sensitivity 99.0%
Specificity 12.9%
NPV 99.8%
Study Size 34,069 patients
NEXUS vs CCR
NEXUS CCR
Sensitivity 99.0% 99.4%
Specificity 12.9% 45.1%
Complexity Simple 3-step
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Disclaimer

This calculator is provided for educational and informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment.

  • Always seek the advice of a qualified healthcare provider with any questions regarding a medical condition.
  • Never disregard professional medical advice or delay seeking it because of information from this tool.
  • Clinical decision-making should always incorporate the full clinical context, patient preferences, and local protocols.
  • The creators of this tool accept no liability for decisions made based on its output.

If you are a patient: please discuss any results with your healthcare provider. This tool is designed for use by medical professionals and may not be appropriate for self-assessment.