Canadia C-Spine rule may have better diagnostic accuracy than NEXUS criteria for assessing imaging of cervical spine injury


Zoe Michaleff, George Institute for Global Health, The University of Sydney, Sydney, Australia, and others reported in the Canadian Medical Association Journal that the Canadian Cervical Spine (C-Spine) rule for assessing the need of imaging following blunt trauma to the cervical spine may have better diagnostic accuracy than the National Emergency X-Radiography Utilization Study (NEXUS) criteria.

Michaleff et al wrote that both the Canadian C-Spine rule and the NEXUS criteria are used to assess the need for imaging in patients with a cervical spine injury following a blunt trauma, but added that there is no consensus about which rule should be preferred. They said that, therefore, the purpose of their study was to “compare the diagnostic accuracy of the Canadian C-Spine rule to that of NEXUS”.

Using data from CINAHL, Embase, and MEDLINE, the authors identified 15 studies that reviewed the Canadian C-Spine rule and/or the NEXUS criteria—with eight reviewing the Canadian C-Spine rule alone, six reviewing the NEXUS criteria alone, and one directly comparing the two rules. They found that the sensitivity of the Canadian C-Spine rule ranged from 0.9 to 1 and its specificity ranged from 0.01 to 0.77, while the sensitivity of the NEXUS criteria ranged from 0.83 to 1 while its specificity ranged from 0.13 to 0.46. With the Canadian C-Spine rule, imaging rates would have been reduced by an average of 42% without missing a clinical important cervical spine injury and the NEXUS criteria would have reduced imaging rates by an average of 30.9% without missing a clinically important cervical spine injury.

Michaleff et al added, in the direct comparison study, that “The Canadian C-Spine rule would have reduced imaging rates by 44% while NEXUS would have reduced rates by 36%.”

The authors commented: “Clinically, our review highlights the effectiveness of the Canadian C-Spine rule and NEXUS in clearing the cervical spine without the need for imaging, while maintaining patient safety.”  However, they added that the lower specificity and false-positive results observed in the study indicated “that many people will continue to undergo necessary imaging.” Concluding they said, “In the only direct comparison, the Canadian C-Spine rule appeared to have better diagnostic accuracy and it should be used over NEXUS to assess the need for cervical spine imaging” and added that future studies would be needed.

Michaeleff told
Spinal News International: “Widespread use of these rules by doctors could lead to substantial reductions in social and financial costs associated with excessive use of X-rays in practice. There is a need to improve both doctors’ use of, and patients’ knowledge of, the effectiveness of these rules in clearing the neck after an injury. There are few to no benefits of imaging every patient with a neck injury, rather these rules are an effective way of assessing a patient’s risk of serious cervical spine injury and need for imaging. Doctors and patients need to be aware that a negative test result when using either rule means that there is no sign of a serious neck injury and therefore there is no need to X-ray the neck.”