BACKGROUND: Houselessness is associated with increased mortality and unmet health needs. Current understanding of traumatic injury in houseless patients is limited. METHODS: This is a retrospective matched cohort study among houseless and housed adults, admitted to an urban, safety net, level I trauma center from 1/1/2018-12/31/2021. Houseless patients were matched with their housed counterparts 1:2 based on age, sex, injury severity score (ISS) and nature of injury. The primary outcome was in-hospital adverse events. Secondary outcomes included hospital length of stay (LOS), outpatient follow-up, emergency department (ED) utilization post-injury, and readmission. Conditional multivariable regression was used to determine associations between the exposure and outcomes. RESULTS: 1413 patients were included
471 houseless patients and 942 matched controls. Median [IQR] age was 42 years [31-58] and median [IQR] ISS was 9 [5-13] for all patients. About 30 % of traumatic injuries were violent in nature. Median [IQR] total LOS was longer for houseless patients (4.4 days [2.0-8.3] vs. 3.1 days [1.4-6.5], p <
0.001). Houseless patients were more frequently admitted to the ICU (5 % versus 3 %, p = 0.045). The rate of any in-hospital adverse event was similar (houseless 17 % vs. housed 16 %, p = 0.537). Adjusting for age, sex, language, insurance, ISS, nature of injury, injury mechanism, ICU admission, and operative intervention, houselessness was inversely associated with outpatient follow-up (OR 0.60, 95 % CI 0.46-0.79) and positively associated with ED representation (OR 2.49, 95 % CI 1.64-3.78) and hospital readmission (OR 4.35, 95 % CI 3.19-5.92). CONCLUSIONS: Housing status was not associated with increased in-hospital morbidity or mortality in trauma patients in a single institution cohort of trauma patients. Unhoused patients had lower odds of completing outpatient injury-specific follow-up and higher odds of utilizing the ED within 30 days of discharge. These findings highlight gaps in post-discharge care coordination and underscore opportunities to improve discharge services for this population.