Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma.

Background: Because clinicians fear missing occult cervical-spine injuries, they obtain cervical radiographs for nearly all patients who present with blunt trauma. Previous research suggests that a set of clinical criteria (d ecision instrument) can identify patients who have an extremely low probabi lity of injury and who consequently have no need for imaging studies. Methods: We conducted a prospective, observational study of such a decision instrument at 21 centers across the United States. The decision instrument required patients to meet five criteria in order to be classified as havin g a low probability of injury: no midline cervical tenderness, no focal neu rologic deficit, normal alertness, no intoxication, and no painful, distrac ting injury. We examined the performance of the decision instrument in 34,0 69 patients who underwent radiography of the cervical spine after blunt tra uma. Results: The decision instrument identified all but 8 of the 818 patients w ho had cervical-spine injury (sensitivity, 99.0 percent [95 percent confide nce interval, 98.0 to 99.6 percent]). The negative predictive value was 99. 8 percent (95 percent confidence interval, 99.6 to 100 percent), the specif icity was 12.9 percent, and the positive predictive value was 2.7 percent. Only two of the patients classified as unlikely to have an injury according to the decision instrument met the preset definition of a clinically signi ficant injury (sensitivity, 99.6 percent [95 percent confidence interval, 9 8.6 to 100 percent]; negative predictive value, 99.9 percent [95 percent co nfidence interval, 99.8 to 100 percent]; specificity, 12.9 percent; positiv e predictive value, 1.9 percent), and only one of these two patients receiv ed surgical treatment. According to the results of assessment with the deci sion instrument, radiographic imaging could have been avoided in the cases of 4309 (12.6 percent) of the 34,069 evaluated patients. Conclusions: A simple decision instrument based on clinical criteria can he lp physicians to identify reliably the patients who need radiography of the cervical spine after blunt trauma. Application of this instrument could re duce the use of imaging in such patients. (N Engl J Med 2000;343:94-9.) (C) 2000, Massachusetts Medical Society.