Dose-response relationship between in-hospital mortality and alcohol following acute injury

Although the relationship between alcohol and injury incidence is well researched, there continues to be dispute about the relationship between alcohol and mortality following an injury. Findings from past studies have varied primarily because of methodological issues and have failed to characterize the dose-response relationship. The main objective of this study was to evaluate the dose response relationship of in-hospital mortality and blood alcohol concentration (BAC). This study was a retrospective analysis of traumatic injuries occurring between 1995 and 2009 as reported by all level 1 and 2 trauma units in the State of Illinois. The study includes all patients with blood alcohol toxicological examination levels ranging from zero to 500 mg/dl (N = 190,612). The Illinois trauma registry includes all patients sustaining traumatic injuries and admitted to a trauma center for ≥12 h. A total of 6733 patients meeting the inclusion criteria died following admission. Patients that were dead on arrival and those that died during the initial assessment within the emergency room were excluded. In the adjusted multivariable model, a decrease in in-hospital mortality was strongly associated with an increase in blood alcohol concentration (adjusted OR = 0.83 per 100 mg/dl units change in BAC; CI 95%: 0.80, 0.85; p < 0.001). The direction of the dose response relationship was consistent across the stratified models, with the exception of patients suffering burns. The largest reduction of in-hospital case fatality rates by blood alcohol concentration was observed among patients suffering penetrating or severe injuries (Injury Severity Score ≥ 16). In the clinical setting, it is important to understand not only how to recognize intoxicated patients, but also how alcohol may affect the course of treatment. The consistency of the findings across the multivariable models indicates that blood alcohol concentration is strongly associated with lower in-hospital mortality among those that survive long enough to receive treatment in specialized trauma units.