Characteristics and Determinants of Infection-Related Readmissions After Traumatic Injury: A Descriptive Analysis

Authors:
Fabiana C Sanchez, Marina Eguchi, Marco J Henriquez, Amin Dehghan, Ricardo A Fonseca, Lindsay M Kranker, Grant Bochicchio

Body of Abstract:
Background:

Urgent readmission after traumatic injury is common and is associated with significant morbidity and cost. This study aims to characterize patients who require unplanned readmission due to infection and to identify factors associated with an increased risk of infection-related readmission.

Methods:

A retrospective analysis of a prospectively maintained registry of adult trauma patients admitted to a Level I trauma center (2018–2024) was performed. Readmission was defined as occurring within 30 days of discharge; deaths and hospice discharges were excluded. We compared demographic, injury-related, and discharge characteristics between groups and conducted descriptive analysis of infection site, microbiology, diagnostics, and need for interventional radiology or operative management.

Results:

Among 5,844 level 1 trauma patients, 213 (3.6%) experienced a 30-day unplanned readmission. Compared with patients who were not readmitted, the readmission cohort was younger (mean age 45.6 vs 52.9 years, p < 0.001), had a higher Injury Severity Score (mean 17.4 vs 13.9, p < 0.001), a longer index admission length of stay (mean 11.0 vs 7.9 days, p < 0.001), and higher Social Vulnerability Index scores (mean 63.6 vs 56.7, p < 0.001). Readmitted patients were more frequently male (70.9% vs 61.8%), Black non-Hispanic (63.4% vs 47.5%), and injured by penetrating mechanisms (41.3% vs 20.5%). Operative management during index admission was more common among readmitted patients (40.8% vs 23.6%). They also had significantly higher rates of leaving against medical advice (10.3% vs 1.9%) and were more often discharged home rather than to a facility. Of the 213 readmissions, 108 (50.7%) were infection-related: 37 intra-abdominal infections (34.3%), 26 wound infections (24.1%), 9 empyema (8.3%), 23 urinary tract infections (21.3%), 6 pneumonias (5.6%), and 7 other infections (6.5%). Intra-abdominal infections were predominantly polymicrobial with anaerobic microbiology and required the highest utilization of CT imaging (61.0% vs 39.0%), interventional radiology procedures (64.1% vs 35.9%), and operative management (54.1% vs 45.9%). Wound infections were mostly Staphylococcus aureus (MRSA/MSSA). Empyema, UTIs, pneumonia, and other infections represented smaller proportions but collectively accounted for nearly half of infection-related readmissions. Conclusions: Readmitted patients demonstrated greater social vulnerability and clinical complexity, indicating groups that may benefit from targeted follow-up and enhanced support. Infection drives a significant proportion of trauma readmissions and is associated with high procedural demands, particularly in intra-abdominal and wound infections. These findings provide a foundation for identifying modifiable risk factors for readmission and developing strategies to reduce preventable infection-related readmissions, such as the prevention of discharge against medical advice and better outpatient support.