Past blood alcohol concentration and injury in trauma center: propensity scoring

Evidence linking alcohol use to injury outcomes remains inconclusive, with prehospital and police department-based studies showing negative effects and hospital-based studies showing no effect or better outcomes.

The purpose of this study was to examine the relationship of blood alcohol concentration (BAC) with injury characteristics and outcomes among trauma patients admitted to a major teaching hospital. In an effort to mitigate selection and confounding bias, propensity scoring methodology was applied, by which trauma patients were randomly assigned to high- and low-BAC groups.

Electronic medical records were retrospectively reviewed for a period of 8 months. Of 1057 patients whose BAC was determined, 667 had BAC ≤ 0.08 g/dL and 390 had BAC > 0.08 g/dL. Injury characteristics were defined as injury type, injury location, and trauma level. Injury outcomes were defined as hospitalization, length of hospital stay, and in-hospital death. Adjusted odds ratios (aOR) and their 95% confidence intervals (CI) were calculated using multivariate logistic regression models and propensity scoring was applied.

A positive relationship was observed between BAC and unintentional injury (aOR = 1.08; 95% CI 1.01-1.17). Although injuries of the extremities were less likely to occur in patients with high BAC (aOR = 0.88; 95% CI 0.80-0.98), head injury was positively associated with high BAC (aOR = 1.27; 95% CI 1.14-1.42). Also, Level I trauma patients had nearly 60% greater odds of having a high BAC than Level II trauma patients.

A high alcohol level in the blood appears to be predictive of more unintentional injury, head injury, and Level I trauma activation and less injuries in extremities.