Homelessness Prolongs Length of Hospital Stay After Traumatic Injury

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People experiencing homelessness exhibit similar rates of morbidity compared with housed patients, but a longer adjusted length of hospital stay.

Challenges in hospital discharge after traumatic injury could lead to an extended length of stay for individuals experiencing homelessness in North America, according to new findings.1

The cohort study involved approximately 1.4 million patient encounters identified in the American College of Surgeons Trauma Quality Programs (ACS-TQP) data. These data showed people experiencing homelessness exhibited similar morbidity rates with matched housed patients but a significantly increased length of stay.

“This work contributes to a growing body of evidence that health-related social drivers such as homelessness can exacerbate health disparities and lead to higher cost for public payer programs,” wrote the investigative team, led by Casey M. Silver, MD, MS, department of surgery, Northwestern University Feinberg School of Medicine.

Homelessness incidence has exacerbated since the onset of the COVID-19 pandemic in 2020, with these individuals experiencing worse health-related quality of life.2 Structural barriers to access to care among those experiencing homelessness increase emergency department use and hospitalizations—together, these factors can lead to significant healthcare costs.3

Traumatic injury is a significant reason for hospitalization among those experiencing homelessness.4 However, the subsequent hospital course, including the incidence of morbidity, surgical procedures, and intensive care unit admission of people experiencing homelessness, is not well understood.1 A prolonged length of stay, a measure of the total cost of care, could reduce the capacity of an emergency department or hospital ward.

In this retrospective cohort study, investigators examined the effect of homelessness status on morbidity and length of stay after traumatic injury and whether these associations were modified by age or Injury Severity Score (ISS). In the ACS-TQP database, patients admitted after an injury and discharged alive from 787 hospitals in North America from January 2017 to December 2018 were identified for analysis. Those experiencing homelessness were identified using the database’s alternate home residence variable.

Length of stay was defined using 2 variables: a continuous, nonnormally distributed outcome variable and a binary variable of whether the length of stay was greater than 30 days. Propensity score matching was performed between those experiencing homelessness and housed patients on sex, insurance, comorbidity, injury mechanism type, and Glasgow Coma Scale score.

A total of 1,441,982 patient encounters (mean age, 55.1 years; 43.0% women) within 787 hospitals were identified in the analysis. Among these encounters, 9065 (0.6%) involved people experiencing homelessness. Compared with housed patients, those presenting with homelessness were less frequently ≥65 years old, more often uninsured, and presented with severe injury (all P <.001).

In the unmatched cohort, individuals experiencing homelessness exhibited higher morbidity rates (221 [2.4%] vs. 25,134 [1.8%]; P <.001), more frequent hemorrhage control surgery (289 [3.2%] vs. 20,331 [1.4%], and ICU admission (2353 [26.0%] vs. 307,714 [21.5%]; P <.001), compared with housed patients. The unadjusted mean length of stay among those experiencing homelessness was five days compared with four days among housed patients (P <.001).

Overall, 8665 pairs admitted to 378 hospitals were analyzed in the propensity score-matched cohort. Between people experiencing homelessness and matched housed patients, the differences in rates of morbidity, hemorrhage control surgery, and ICU admission were not statistically significant.

Upon multivariable analysis, individuals experiencing homelessness showed a 22.1% longer adjusted length of stay (incident rate ratio [IRR], 1.22 [95% CI, 1.19 - 1.25]) after controlling for age, ISS, morbidity, hemorrhage control surgery, and ICU admission. Overall, Silver and colleagues noted the highest increase in length of stay was in people experiencing homelessness who were ≥65 years old (IRR, 1.42 [95% CI, 1.32 - 1.54]).

The direct correlation between homelessness and length of stay was highest for those experiencing minor injury (ISS, 1 to 8), for a 30% increased adjusted length of stay (IRR, 1.30 [95% CI, 1.25 to 1.35]). Silver and colleagues noted the moderation of ISS on the direct association between homelessness and adjusted length of stay was statistically significant (P <.001).

“These findings have significant implications for quality and costs of care for people experiencing homelessness and underscore potential opportunities to reduce disparities in trauma outcomes and improve hospital resource use among those with injuries,” investigators wrote.


  1. Silver CM, Thomas AC, Reddy S, et al. Morbidity and Length of Stay After Injury Among People Experiencing Homelessness in North America. JAMA Netw Open. 2024;7(2):e240795. doi:10.1001/jamanetworkopen.2024.0795
  2. US Department of Housing and Urban Development. The 2020 Annual Homeless Assessment Report (AHAR) to Congress. January 2021. Accessed February 29, 2024.
  3. Silver CM, Thomas AC, Reddy S, Sullivan GA, Plevin RE, Kanzaria HK, Stey AM. Injury Patterns and Hospital Admission After Trauma Among People Experiencing Homelessness. JAMA Netw Open. 2023 Jun 1;6(6):e2320862. doi: 10.1001/jamanetworkopen.2023.20862. PMID: 37382955; PMCID: PMC10311388.
  4. Rollings KA, Kunnath N, Ryus CR, Janke AT, Ibrahim AM. Association of Coded Housing Instability and Hospitalization in the US. JAMA Netw Open. 2022 Nov 1;5(11):e2241951. doi: 10.1001/jamanetworkopen.2022.41951. PMID: 36374498; PMCID: PMC9664259.