Association between emergency department to intensive care units time and in-hospital mortality: an analysis of the MIMIC-IV database.

Abstract

Objectives: The association between the duration from the emergency department (ED) to the intensive care units (ICUs) and in-hospital mortality among patients admitted directly to the ICUs from the ED remains controversial. This study aimed to use data from the Medical Information Mart for Intensive Care-IV database to explore the relationship between the ED to ICUs time and patient outcomes.

Design: Retrospective observational study.

Setting: Admissions to the Beth Israel Deaconess Medical Center intensive care from 2008 to 2019.

Participants: A total of 15 246 adult patients were identified as admitted directly from the ED to the ICUs during their first hospitalisation. After excluding those without recorded ED registration times and those with a hospital-to-ICU admission interval exceeding 6 hours (n=2432), the final analysis cohort comprised 12 703 patients.

Primary and secondary outcome measures: The primary outcome was in-hospital all-cause mortality. Secondary outcomes included 28-day all-cause mortality and length of stay in ICU and hospital.

Results: The median ED to ICUs time was 3.98 hours. Longer ED to ICUs times were associated with lower in-hospital mortality, decreasing from 17.6% in the shortest to 12.2% in the longest interval group, and shorter ICU stays. After propensity score weighting, adjusted logistic regression models confirmed the inverse association between longer ED to ICUs time and in-hospital mortality (OR: 0.75, 95% CI: 0.69 to 0.82, p<0.01). Restricted cubic spline analysis showed a non-linear decline in mortality risk with increasing ED to ICUs time, with a sharper reduction after 5.65 hours. Kaplan-Meier curves indicated consistently better survival in the longest interval group (p<0.01). Sensitivity analysis, reintroducing patients with hospital to ICUs times over 6 hours, confirmed the robustness of these results.

Conclusions: Longer ED to ICUs time is linked to lower mortality and shorter ICU length of stay, suggesting that appropriately extending ED stays may benefit critically ill patients.