Head trauma sustained under the influence of alcohol is a predictor for future traumatic brain injury: a long‐term follow‐up study

Abstract

Hazardous drinking may result in recurrent head trauma. It was investigated whether head trauma sustained under the influence of alcohol is a predictor of future traumatic brain injury (TBI). All subjects with head trauma (n = 827) brought to the emergency room at Oulu University Hospital during 1999 were identified and followed up until death or the end of 2009. The National Hospital Discharge Register and hospital charts were used to identify TBIs during the follow-up and Kaplan-Meier curves and the Cox proportional hazards model were used to characterize predictors of TBI. During the total follow-up of 7386 person-years, 52/827 subjects sustained a new head trauma with TBI and the risk of TBI was significantly (P = 0.005) higher amongst subjects who had been under the influence of alcohol at the time of the index trauma in 1999. New TBI occurred under the influence of alcohol in 30/52 cases (57.7%). An alcohol-related index trauma [adjusted hazard ratio (HR) 2.51, 95% confidence interval (CI) 1.38-4.56, P < 0.01] and history of TBI (HR 3.39, 95% CI 1.32-8.72, P < 0.05) were independent risk factors for subsequent TBI after adjustment for sex and age. A history of harmful drinking was also a significant risk factor (adjusted HR 10.37, 95% CI 5.53-19.43, P < 0.001). In the subset of 396 patients having an index head trauma without TBI, this being alcohol related was also a significant risk factor for subsequent TBI after adjustment for sex, age and history of TBI (HR 3.54, 95% CI 1.36-9.18, P = 0.009). Even head trauma without TBI under the influence of alcohol implies an elevated risk of subsequent TBI. A brief intervention to reduce hazardous drinking is needed to prevent TBI.