Regional variability in the use of CT for patients with suspected mild traumatic brain injury

Objective: To investigate the use of computed tomography (CT) scans in patients with suspected acute mild traumatic brain injury (mTBI) presenting to emergency departments. Method: 850 potential mTBI cases were identified through reviews of three months of health records from nine selected emergency departments across the province of Ontario. Records for review were selected using the International Classification of Disease, 9th revision, Clinical Modification codes and Injury codes. Results: Patients who received head CT were significantly older (p<0.01), had documented loss-of-consciousness (LOC) &/or Post-Traumatic Amnesia (PTA) (p<0.001), documented nausea (p<0.01), documented vomiting (p<0.001), abnormal neurological exam results (p<0.01), had visited an urban center (p<0.001), and/ or arrived by ambulance (p<0.001). The significant predictors of CT scan prescription (in a forward stepwise logistic regression) were urban location of hospital (OR=5.14; p≤0.001), LOC &/or PTA (OR=4.83; p≤0.001), vomiting (OR=2.56; p≤0.01), arrival by ambulance (OR=2.15; p≤0.001), nausea (OR=1.92; p=≤0.02) and older age (OR=1.02; p≤0.01). Conclusion: These data extend our knowledge regarding the use of CT during acute diagnosis and management of suspected mTBI patients. In addition to confirming previously reported risk factors of intracranial complication, geographical location of hospital and arrival mode were found to be significant predictors of CT use. The results suggest that the management patterns for acute mTBI are inconsistent. The implications of this are discussed.