Trokos

Test library › Neck

NEXUS low-risk criteria

For: Clinically significant cervical spine injury after blunt trauma (need for imaging)

Website-only page: no separate test card in the book, which discusses this in its ‘The neck’ chapter.

A neck injury after blunt trauma that the NEXUS study defined in advance as clinically significant. The NEXUS criteria decide who needs imaging; they do not diagnose the injury.

Treat with caution (see below)
Sensitivity99.6%
Specificity12.9%
LR+ (positive)1.14
LR− (negative)0.03

Likelihood ratios calculated from the published sensitivity and specificity for clinically significant injury.

Caution: In a later head-to-head study (Stiell 2003) sensitivity was only 90.7% (LR− 0.25), so a negative may not rule injury out as reliably.

These figures have not been confirmed against the full paper (checked against the abstract or a secondary source only).

How it is done

For patients after blunt trauma. The patient is low risk, and needs no imaging, only if ALL five are met: no midline neck tenderness; no focal neurological deficit; normal alertness; no intoxication; and no painful distracting injury. If any one is not met, image.

What the studies found

Decision rule for imaging after neck trauma — a rule-out tool. Meeting all five criteria means imaging is not needed; failing any one means 'image', not 'injury present' (LR+ only 1.14). Hoffman 2000 studied 34,069 patients of all ages, children included, at 21 US centres. Figures are for clinically significant injury: sensitivity 99.6% (95% CI 98.6–100%), specificity 12.9%. For any neck injury, sensitivity was 99.0% (95% CI 98.0–99.6%); 8 of 818 injuries were missed. With such low specificity, most patients still need imaging. In the later head-to-head Canadian study (Stiell 2003), NEXUS sensitivity was only 90.7% and specificity 36.8% (LR− 0.25); it missed 16 important injuries, against 1 for the Canadian C-spine Rule.

What the numbers mean

  • Positive result: barely informative: a positive result changes little.
  • Negative result: see the caution above before relying on this result.

The ladder: what a result does to your estimate

If you thoughtAfter a positiveAfter a negative
10%11%under 1%
30%33%1%
50%53%3%

Calculated from the likelihood ratios above. Read the caution above before relying on these. For any other starting estimate, use the probability calculator.

Work out what a result means for your patient: probability calculator

Source

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 (NEXUS). N Engl J Med. 2000;343(2):94–99. Journal article (DOI) · single study
Also cited: 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. Journal article (DOI)

Website-only page, added to the library on 9 October 2026. Rule It In, Rule It Out discusses this but has no separate test card for it. Figures independently checked against the sources cited above; any note above says where only the abstract could be checked.

Get the book for the neck questions that matter: nerve root or referred pain, which myelopathy signs count, and when a neck after trauma needs imaging

The ‘The neck’ chapter of Rule It In, Rule It Out discusses this, alongside how to do and read each test in the chapter.

Coming in late 2026 as a PDF and a paperback. Join the list to hear when it's out

One study, one test, once a month

Rule It In is a free evidence letter for musculoskeletal clinicians: one recent study explained, one examination test with its real numbers. From Trokos, publisher of Rule It In, Rule It Out.

Free when you confirm your email: a one-page PDF of the strongest special tests to rule in and rule out, with tests that carry a caution flagged separately.