In reply

Abstract

We would like to thank Hoffman et al for their interest in our article and their insightful questions regarding its Discussion section. We, too, appreciate the differences between the 2 instruments and welcome discourse on their merits. We felt an obligation to discuss the findings of our study in the context of the current literature on the same subject and to provide available evidence relevant to this task. As comparisons will inevitably be made between the Canadian C-Spine rule and the formidable National Emergency X-Radiography Utilization Study (NEXUS) work, we thought it appropriate to include the latter in our discussion. We acknowledge that the studies had different inclusion criteria and were derived in different practice populations, and we did not dispute the findings of the NEXUS investigators in their population. This is precisely why we thought it was important to discuss the NEXUS instrument as it would have performed with our population. The Canadian C-Spine and CT Head Study included all patients with potential blunt trauma to the neck, including those for whom imaging was not obtained. We thought this was a more comprehensive approach that reflected the reality of practice. A comparative validation of both the Canadian C-Spine rule and the NEXUS instrument has been completed.1Stiell IG Clement C 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: 2510-2518Crossref PubMed Scopus (451) Google Scholar We hypothesized that one reason for the lower sensitivity demonstrated in a retrospective application of the NEXUS instrument to Canadian patients may have been low interobserver reliability. This hypothesis was based on results of a previous study detailing the development of the Canadian C-spine rule, and this was acknowledged in our article.2Stiell IG Wells GA Vandemheen K et al.The Canadian Cervical Spine Radiography rule for alert and stable trauma patients.JAMA. 2001; 286: 1841-1848Crossref PubMed Scopus (846) Google Scholar We believe that the difference in results between our application of the NEXUS instrument and those of Hoffman et al3Hoffman JR Mower WR Wolfson AB et al.Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma.N Engl J Med. 2003; 343: 94-99Crossref Scopus (947) Google Scholar in the original study justify our comments about the need for further research into the NEXUS criteria before application in populations other than the US-based population in which it was derived. Notwithstanding the writers' final paragraph, we also applaud the contributions of both initiatives to this important clinical problem and acknowledge that each may have appropriate applicability depending on prevailing circumstances. It is important, however, for clinicians to understand the basis for these decision instruments, and we would welcome further open debate of the issues, such as was done when the results of our assessment of the NEXUS sensitivity were presented and debated in an open abstract session at the Society for Academic Emergency Medicine.4Stiell IG McKnight R Wells GA et al.Application of the NEXUS low-risk criteria for cervical spine radiography in Canadian emergency departments [abstract].Acad Emerg Med. 2000; 7: 566Google Scholar The resulting article will appear in print in the near future.5Dickinson G Stiell IG Schull M et al.Retrospective application of the NEXUS low-risk criteria for cervical spine radiography in Canadian emergency departments.Ann Emerg Med. 2004; 43: 507-514Abstract Full Text Full Text PDF PubMed Scopus (55) Google Scholar 1The resulting article has since been published.5Dickinson G Stiell IG Schull M et al.Retrospective application of the NEXUS low-risk criteria for cervical spine radiography in Canadian emergency departments.Ann Emerg Med. 2004; 43: 507-514Abstract Full Text Full Text PDF PubMed Scopus (55) Google Scholar1The resulting article has since been published.5Dickinson G Stiell IG Schull M et al.Retrospective application of the NEXUS low-risk criteria for cervical spine radiography in Canadian emergency departments.Ann Emerg Med. 2004; 43: 507-514Abstract Full Text Full Text PDF PubMed Scopus (55) Google Scholar