nexus vs. canadian c-spine rule (ccr) in predicting cervical spine injuries; a systematic review and meta-analysis

Introduction: clinical decision tools have been shown to reduce imaging rates for clearance of suspected cervical spine injury (csi). this review provides more comprehensive evidence on the diagnostic capabilities of national emergency x-radiography utilization study (nexus) and canadian c-spine rule (ccr) in this regard. method: a systematic review of the current literature was performed on studies published until jan 26th, 2023, in databases of medline, scopus, web of science, and embase, investigating the performance of nexus and ccr in blunt trauma patients. quadas-2 and grade guidelines were used to assess the quality and certainty of evidence. all analyses were performed using the stata 14.0 statistical analysis software. results: 35 articles comprising 70000 patients for nexus and 33000 patients for ccr were included in this review. nexus and ccr were evaluated to have a sensitivity of 0.94 (95% confidence interval (ci): 0.88 to 0.98) and 1.00 (95% ci: 0.98 to 1.00) in the detection of any csi and 0.95 (95% ci: 0.89 to 0.98) and 1.00 (95% ci: 0.95 to 1.00) in the detection of clinically important csi. the area under the curve (auc) of nexus and ccr was 0.85 and 0.97 for any csi and 0.78 (95% ci: 0.74 to 0.81) and 0.94 (95% ci: 0.91 to 0.96) for clinically important csi. conclusion: our study demonstrates that both nexus and ccr can be used in ruling out patients with low risk of csi, and ccr was shown to have superior performance. even though these tools have low specificity, their application can still greatly reduce the number of radiographic imaging performed in emergency departments.