Clinical decision rule
NEXUS Rules
NEXUS Low-Risk Criteria for Cervical Spine Imaging
The NEXUS low-risk criteria allow the cervical spine to be cleared without imaging after blunt trauma when all five findings are absent — midline cervical tenderness, focal neurological deficit, altered alertness, intoxication and a distracting injury — with a reported sensitivity of about 99% for clinically significant injury.
What the NEXUS category means
NEXUS scores run from 0 to 1, where a lower score is better. The bands below are conventional reporting categories, not diagnostic cut-offs.
- Imaging not indicated0–0
- Cannot clear clinically1–1
Published criteria and reliability
The published cut-offs that define this instrument, and the measured agreement between observers using it. Each is reported with the population it was derived in.
| Type | Value | Subscale | Population | Follow-up | Source |
|---|---|---|---|---|---|
| Criterion | Sensitivity 99.6%, specificity 12.9% | — | Blunt trauma, NEXUS validation cohort of 34,069 patients | — | Hoffman JR 2000 |
| Criterion | Negative predictive value 99.8% | — | Blunt trauma, NEXUS validation cohort | — | Hoffman JR 2000 |
| Criterion | Canadian C-Spine Rule had higher sensitivity (99.4% vs 90.7%) and specificity in direct comparison | — | Alert, stable trauma patients | — | Stiell IG 2003 |
Criterion is a published cut-off, definition or performance figure belonging to a classification or decision rule — it is not a change score and should not be read as one.
How the score is calculated
Stated in full so the calculation can be independently checked, and reproduced by hand if needed.
The five low-risk criteria are assessed independently. Cervical spine radiography is not required only when every one of the five is absent. The presence of any single criterion means the cervical spine cannot be cleared clinically and imaging is indicated. The rule is designed to rule out injury rather than to predict it, so specificity is deliberately low.
Instrument profile
- Developer
- Jerome R. Hoffman and colleagues
- Institution
- UCLA, National Emergency X-Radiography Utilization Study group
- First published
- 2000
- Items
- 5
- Response format
- Five present/absent criteria
- Score range
- 0 to 1
- Direction
- Lower score = better
- Completion time
- About 1 minutes
- Age range
- All ages in the original study, though performance is weaker at the extremes of age
- Regions
- Spine
- Conditions
- Blunt cervical spine trauma, Neck injury, Cervical spine fracture
- Validity
- Validated prospectively in more than 34,000 patients, one of the largest decision-rule validation cohorts in emergency medicine.
- Reliability
- Specificity is very low, so a large share of patients meeting one criterion will have no injury. The rule reduces imaging modestly compared with the Canadian C-Spine Rule, which discriminates better in alert, stable patients.
When to use the NEXUS
Well suited to
- Blunt trauma patients in whom cervical spine injury is being considered and the patient can be examined reliably.
- Settings where a simple, memorable five-item rule is preferred over the Canadian C-Spine Rule’s branching algorithm.
Limitations and poor fits
- Penetrating trauma, which the rule does not cover.
- Patients over 65 and young children, where sensitivity is lower and age-specific pathways are preferred.
- Any patient who cannot be examined reliably — the criteria assume a cooperative, assessable patient.
NEXUS compared with other instruments
Instruments measuring a related construct, with the practical difference between them.
| Instrument | Items | Range | What it adds |
|---|---|---|---|
| Canadian C-Spine Rule | 3 | 0–1 | The Canadian C-Spine Rule decides whether an alert, stable blunt trauma patient needs cervical spine radiography through three sequential steps — high-risk factors, low-risk factors, and the ability to actively rotate the neck 45 degrees each way — with a reported sensitivity of about 99% for clinically significant injury. |
| Ottawa Ankle Rules | 7 | 0–1 | The Ottawa Ankle Rules determine whether an acute ankle or midfoot injury requires radiographs, based on bone tenderness at four specific sites and the ability to bear weight for four steps; they are approximately 98% sensitive for clinically significant fractures. |
| Ottawa Knee Rule | 5 | 0–1 | The Ottawa Knee Rule determines whether an acute knee injury requires radiographs using five criteria — age 55 or over, isolated patellar tenderness, fibular head tenderness, inability to flex to 90 degrees, and inability to bear weight for four steps — and is close to 99% sensitive for clinically significant fractures. |
Copyright and permitted use
Published openly because it is the question every clinician and researcher asks before using an instrument, and almost nobody answers it.
The NEXUS low-risk criteria are a published clinical decision rule. The criteria are freely reproducible and no licence is required.
References
- Hoffman JR, Mower WR, Wolfson AB, Todd KH, Zucker MI. Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma. New England Journal of Medicine. 2000.PMID 10891516
- Stiell IG, Clement CM, McKnight RD, et al.. The Canadian C-Spine Rule versus the NEXUS Low-Risk Criteria in patients with trauma. New England Journal of Medicine. 2003.PMID 14695411
Editorial status
This page has not yet been signed off by a named clinical reviewer. The scoring logic is stated in full above so it can be independently verified, and every threshold is traceable to its source. See our editorial methodology.