Evaluation of a Modified Prediction Instrument to Identify Significant Pediatric Intracranial Injury After Blunt Head Trauma

In the NEXUS II cohort, a modified version of the University of California-Davis Rule misclassified a substantial proportion of pediatric patients with clinically important blunt head injury. Although we cannot evaluate the exact University of California-Davis Rule, we demonstrate that using stricter definitions of “headache” and “vomiting” and different wording than in the original study may have unintended or negative consequences. We emphasize the importance of careful attention to precise definitions of clinical predictors when a decision instrument is used.