Influence of alcohol on in-hospital survival rate among patients with traumatic brain injury: a nationwide cohort study

Abstract

The impact of alcohol on the prognosis of patients with traumatic brain injury (TBI) remains unclear. While some reports suggest that alcohol may exert neuroprotective effects, others indicate that it can worsen neurological outcomes. This study aimed to evaluate the influence of alcohol consumption on TBI outcomes using a nationwide database in Japan. We analyzed data from approximately 290 hospitals contributing to the Japan Trauma Data Bank between 2004 and 2018. Patients with head injuries and documented pre-injury alcohol consumption were included. To adjust for potential confounders and institutional clustering, we employed propensity score methods—specifically inverse probability weighting (IPTW) and overlap weighting—and conducted multiple logistic regression with a generalized estimating equation. Covariates in the propensity score model included age, sex, day of the week, time of injury, period of injury, and past medical history. The primary outcome was in-hospital survival. Additionally, we fitted a multivariate logistic regression model (with survival as the outcome) to identify potential interactions and confounders. This model included type of trauma (blunt or penetrating), cause and setting of trauma, head Abbreviated Injury Scale score, multiple trauma status, the Injury Severity Score, and the propensity score. Of the 83,789 patients who met the inclusion criteria, 15,752 had reported alcohol consumption prior to injury (alcohol group) and 68,037 did not (non-alcohol group). In-hospital survival was 91.5% in the alcohol group and 86.4% in the non-alcohol group (risk difference: 5.2%; 95% CI: 4.7–5.7). After adjustment, the alcohol group maintained a higher in-hospital survival rate (IPTW: 92.0% vs. 86.1%, risk difference: 6.2%; 95% CI: 5.9–6.2; overlap weighting: 91.7% vs. 85.4%, risk difference: 7.0%; 95% CI: 6.1–7.8). In the multivariate logistic regression, preinjury alcohol consumption was associated with higher survival (odds ratio: 1.58, 95% CI: 1.47–1.70, p < 0.001). In this nationwide study, preinjury alcohol consumption was associated with higher in-hospital survival among patients with TBI. Further research is warranted to elucidate the underlying mechanisms and confirm these findings in more diverse populations.