Retrospective application of the NEXUS low-risk criteria for cervical spine radiography in Canadian emergency departments.
OBJECTIVE
We evaluate the accuracy, reliability, and potential impact of the National Emergency X-Radiography Utilization Study (NEXUS) low-risk criteria for cervical spine radiography, when applied in Canadian emergency departments (EDs).


METHODS
The Canadian C-Spine Rule derivation study was a prospective cohort study conducted in 10 Canadian EDs that recruited alert and stable adult trauma patients. Physicians completed a 20-item data form for each patient and performed interobserver assessments when feasible. The prospective assessments included the 5 individual NEXUS criteria but not an explicit interpretation of the overall need for radiography according to the criteria. Patients underwent plain radiography, flexion-extension views, and computed tomography at the discretion of the treating physician. Patients who did not have radiography were followed up with a structured outcome assessment by telephone to determine clinically important cervical spine injury, a previously validated outcome measurement. Analyses included sensitivity and specificity with 95% confidence interval (CI), kappa coefficient, and potential radiography rates.


RESULTS
Among 8,924 patients, 151 (1.7%) patients had an important cervical spine injury. The combined NEXUS criteria identified important cervical spine injury with a sensitivity of 92.7% (95% CI 87% to 96%) and a specificity of 37.8% (95% CI 37% to 39%). Application of the NEXUS criteria would have potentially reduced cervical spine radiography rates by 6.1% from the actual rate of 68.9% to 62.8%. Of 11 patients with important injuries not identified, 2 were treated with internal fixation and 3 with a halo.


CONCLUSIONS
This retrospective validation found the NEXUS low-risk criteria to be less sensitive than previously reported. The NEXUS low-risk criteria should be further explicitly and prospectively evaluated for accuracy and reliability before widespread clinical use outside of the United States.
Dickinson
Garth
G
Department of Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada.
Stiell
Ian G
IG
Schull
Michael
M
Brison
Robert
R
Clement
Catherine M
CM
Vandemheen
Katherine L
KL
Cass
Daniel
D
McKnight
Douglas
D
Greenberg
Gary
G
Worthington
James R
JR
Reardon
Mark
M
Morrison
Laurie
L
Eisenhauer
Mary A
MA
Dreyer
Jonathan
J
Wells
George A
GA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002170:Canada; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging* / Q000293:injuries*; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013119:Spinal Cord Injuries / Q000000981:diagnostic imaging*; D013124:Spinal Injuries / Q000000981:diagnostic imaging; D014949:Wounds, Nonpenetrating / Q000000981:diagnostic imaging