Psychiatric comorbidity and trauma: impact on inpatient outcomes and implications for future management

Purpose: This study aimed to quantify the impact of pre-existing psychiatric illness on inpatient outcomes after major trauma and to assess acuity of psychiatric presentation as a predictor of outcomes. Methods: A retrospective single-center cohort study identified adult trauma patients with an Injury Severity Score (ISS) ≥ 16 between January 2018 and December 2019. Bivariate analysis assessed patient characteristics, injury characteristics, and injury outcomes between patients with and without psychiatric comorbidity. A sub-group analysis explored further effects of psychiatric history and need for inpatient psychiatric consultation on outcomes. Results: Of 640 patients meeting inclusion criteria, 99 patients (15.4%) had at least one psychiatric comorbidity. Patients with psychiatric comorbidity sustained distinct mechanisms of injury and higher in-hospital morbidity (44% vs. 26%, OR 1.97, 95% CI 1.17–3.3, p = 0.01), including pulmonary morbidity (31% vs. 21%, p < 0.01), neurologic morbidity (18% vs 7%, p < 0.01), and deep wound infection (8% vs. 2%, p < 0.01) than the control cohort. Psychiatric patients also had significantly greater median intensive care unit (ICU), length of stay (LOS) (1 day vs. 0 days, p = 0.04), median inpatient ward LOS (10 days vs. 7 days, p = 0.02), and median overall hospital LOS (16 days vs. 11 days, p < 0.01). In sub-group analysis, patients with a history of psychiatric illness alone had comparable outcomes to the control group. Conclusions: Psychiatric comorbidity negatively impacts inpatient morbidity and inpatient LOS. This effect is most pronounced among acute psychiatric episodes with or without a history of mental illness.