title: Retrospective application of the NEXUS low-risk criteria for cervical spine radiography in Canadian emergency departments.
abstract: 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.
authors.affiliation: Department of Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Garth
authors.initials: G
authors.lastname: Dickinson
authors.forename: Ian G
authors.initials: IG
authors.lastname: Stiell
authors.forename: Michael
authors.initials: M
authors.lastname: Schull
authors.forename: Robert
authors.initials: R
authors.lastname: Brison
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Clement
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Vandemheen
authors.forename: Daniel
authors.initials: D
authors.lastname: Cass
authors.forename: Douglas
authors.initials: D
authors.lastname: McKnight
authors.forename: Gary
authors.initials: G
authors.lastname: Greenberg
authors.forename: James R
authors.initials: JR
authors.lastname: Worthington
authors.forename: Mark
authors.initials: M
authors.lastname: Reardon
authors.forename: Laurie
authors.initials: L
authors.lastname: Morrison
authors.forename: Mary A
authors.initials: MA
authors.lastname: Eisenhauer
authors.forename: Jonathan
authors.initials: J
authors.lastname: Dreyer
authors.forename: George A
authors.initials: GA
authors.lastname: Wells
mesh_terms: 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