Emergency Department Length of Stay in Trauma: A Marker of Triage Priority and Workflow Rather Than Outcome Risk

Background Emergency department (ED) length of stay (LOS) is commonly used as a trauma-system performance measure, but in trauma it may reflect triage priority and disposition workflow rather than clinical risk. We evaluated whether trauma activation was associated with ED LOS and whether ED LOS independently predicted adverse outcomes. Methods We performed a retrospective cohort study of adult trauma encounters at an ACS-verified Level I trauma center from January 2018 through January 2020. Higher activation (partial/full) was compared with lower activation (consult/no activation). Outcomes were ED LOS, a nonmortality performance-improvement (PI)-listed adverse-event composite, in-hospital mortality, and 30-day readmission. Multivariable logistic regression adjusted for age, sex, Injury Severity Score, transfer status, activation group, and mechanism. Results Among 5055 encounters, 2889 (57.2%) had higher activation and 2166 (42.8%) lower activation. Median ED LOS was shorter with higher activation (148 vs 323 minutes; P < 0.001). Unadjusted mortality (5.8% vs 1.6%; P < 0.001) and adverse events (10.1% vs 4.5%; P < 0.001) were higher, while readmission was similar (2.7% vs 2.2%; P = 0.301). Adjusted ED LOS was not associated with the nonmortality PI composite (OR/h, 1.00; 95% CI, 0.95-1.06; P = 0.908) but was inversely associated with mortality (OR/h, 0.82; 95% CI, 0.72-0.94; P = 0.005); this association did not persist after excluding deaths before inpatient admission. Conclusions Higher activation was associated with shorter ED LOS despite greater injury severity. ED LOS was not independently associated with the nonmortality PI-listed adverse-event composite and should be interpreted as a marker of triage priority, workflow, and disposition rather than as an isolated outcome endpoint.