Development of a new clinical decision rule for cervical CT to detect cervical spine injury in patients with head or neck trauma

Abstract

Objective Previous cervical spine imaging decision rules have been based on positive findings on plain X-ray and are limited by lack of specificity, age restrictions and complicated algorithms. We previously derived and validated a clinical decision rule (Rule 1) for detecting cervical spine injury (CSI) on CT in a single-centre study. This recommended CT for patients with (1) GCS score <14, (2) GCS 14-15 and posterior cervical tenderness or neurological deficit, (3) age ≥60 years and fall down stairs, or (4) age <60 and injured in a motorcycle collision or fallen from height. This study assessed the accuracy and reliability of this rule and refined the rule. Methods We conducted a prospective, dual-centre study at two Japanese EDs between August 2012 and March 2014. Patients with head or neck injury ≥16 years of age were included. Clinical data were collected from medical records. Imaging was at the discretion of the treating physician. CSI was diagnosed as a fracture or dislocation seen on CT; patients who were not imaged were followed for 14 days. We analysed the sensitivity and specificity of Rule 1 and refined it post hoc using recursive partitioning. Results 1192 patients were enrolled. 927 completed follow-up. Of these, 584 (63.0%) underwent CT imaging and 38 had CSI. Sensitivity and specificity of Rule 1 were 92.1% (95% CI 79.2% to 97.3%) and 58.6% (95% CI 55.4% to 61.9%). A second rule (Rule 2) was derived recommending CT for those with any of the following: GCS <14, cervical tenderness, neurological deficit or mechanism of injury (fall down stairs, motorcycle collision or fall from height) without age limits. Sensitivity and specificity were 100% (95% CI 90.8% to 100%) and 51.9% (95% CI 48.6% to 55.2%), respectively. Conclusions Our initial CT decision rule had lower sensitivity than in our initial validation study. A refined decision rule based on GCS, neck tenderness, neurological deficit and mechanism of injury showed excellent sensitivity with a small loss of specificity. Rule 2 will now need validation in an independent cohort.