Background: Previous studies have reported inconsistent results on the mortality from trauma among psychiatric patients comparing to non-psychiatric population, which may be partly explained by the inclusion of both suicidal and accidental trauma. This study aimed to investigate the association of psychiatric diagnoses on admission with the outcomes of hospitalized patients for accidental trauma, namely road traffic injury. Methods: Detailed information of patients aged 15 years or older who were hospitalized for road traffic injury between 2004 and 2017 was extracted from the Japan Trauma Data Bank. The primary outcome was to compare in-hospital mortality between patients with and without a psychiatric disorder. We also conducted a subgroup analysis among patients with and without a serious head injury. Results: Altogether, 85,069 patients were included. Of these, 3,895 patients (4.6%) had a psychiatric diagnosis. The in-hospital mortality rate was significantly lower among patients with a psychiatric diagnosis than those without (5.4% vs. 8.3%; adjusted odds ratio [OR] 0.57, 95% confidence interval [CI] 0.47-0.70, p<0.001). In a subgroup analysis of patients with a serious head injury, in-hospital mortality was significantly lower in patients with a psychiatric diagnosis than in those without (10.5% vs. 17.3%; adjusted OR 0.48, 95% CI 0.37-0.62, p<0.001); in-hospital mortality of patients without a serious head injury showed no differences between patients with or without a psychiatric diagnosis (2.8% vs. 3.5%; adjusted OR 0.84, 95% CI 0.61-1.16, p=0.295). Conclusions: In-hospital mortality from road traffic injury was significantly lower among patients with a psychiatric diagnosis than those without, which was primarily evident in a subgroup of patients with a serious head injury. While further replication is necessary, results might be indicative of the neuroprotective effect of psychotropic medications.
ASJC Scopus subject areas