Emergency Department-to-Intensive Care Unit Transfer Delay and Mortality in Critically Ill Adults: A 5-Year Retrospective Cohort Study.

BACKGROUND: Emergency department (ED)-to-intensive care unit (ICU) delay may reflect access block, but prior studies often combine predecision care and postdecision boarding. OBJECTIVES: To evaluate whether total ED registration-to-ICU-bed delay >4 h and postdecision boarding were associated with mortality among adults reaching an ICU bed. METHODS: We conducted a 5-year retrospective cohort of adults transferred from the ED to two level-3 general ICUs at a tertiary training and research hospital. Primary models used early-ED severity-adjusted robust Poisson regression; supportive analyses examined decision-to-ICU boarding, continuous delay, period-specific and COVID-19-negative cohorts, matching, and time-to-event outcomes. RESULTS: Among 691 ED-to-study-ICU candidate records, 650 adults were analyzed; 351 (54.0%) had delay >4 h. Median total transfer time was 4.3 h: 1.3 h before ICU decision and 3.0 h after ICU acceptance. Delay >4 h was associated with higher in-hospital mortality (adjusted risk ratio [aRR] 2.01; 95% CI: 1.46-2.76) and ICU mortality (aRR: 1.70; 95% CI: 1.20-2.42). Adjusted in-hospital mortality was 27.5% versus 13.8% (adjusted risk difference +13.7 percentage points). Postdecision boarding >4 h was associated with in-hospital mortality (adjusted odds ratio [aOR] 1.82; 95% CI: 1.21-2.73), and each boarding hour was associated with higher death odds (aOR 1.14; 95% CI: 1.06-1.24). CONCLUSION: Among adults reaching a study ICU bed, ED-to-ICU delay was common and associated with mortality. Most delay accrued after ICU acceptance, identifying postdecision boarding as a practical target.