The Paradox of Resilience: Lower Mortality Among Unhoused Trauma Patients in the Pacific Northwest

There is a gap in knowledge in the role chronic stress plays in response to subsequent acute stressors, with equipoise as to whether chronic stress may be protective. To study the possibility that individuals who experience chronic stress may be more resilient to an acute stressor, we aim to measure the time-to-event differences between housed and unhoused trauma patients after an acute injury, with reduced time to recovery as a marker of resilience. We conducted a retrospective, observational cohort study of trauma patients at a single center (N=7,666) separated by housing status from 2016-2019. Cox proportional hazards modeling, competing risk, and zero-inflated negative binomial regression was used to assess in-hospital mortality, differences in time to ICU discharge, and outcome-free survival at 60 days by housing status, when adjusting for trauma-related covariates. Unhoused patients had a 34.5% lower hazard of all-cause in-hospital mortality compared to housed (HR 0.66, 95% CI: 0.44-0.98, p-value=0.04). There was no difference in the time to ICU discharge, number of days liberated from ventilation, nor number of days spent out of the ICU. However, unhoused trauma patients had longer hospital admissions. Unhoused trauma patients had significantly lower all-cause in-hospital mortality compared to housed trauma patients, despite having arrived in more critical condition.