Outcomes of boarding critically ill patients in U.S. EDs: A systematic review and meta-analysis

Boarding is the practice of holding patients in the emergency department (ED) or a temporary location after the decision to admit or transfer has been made. Previous literature suggests that ED Length of Stay (LOS), prolonged in boarded patients, is linked to worse outcomes. We conducted a systematic review and meta-analysis (SR/MA) to evaluate the differences in mortality and hospital LOS in ED-boarding (EDB) and non-ED boarding (non-EDB) critically ill patients in U.S. EDs.

A systematic search was performed with medical librarians using major health science databases from 2012 through December 2024. Eligible studies included observational or randomized trials involving adults comparing EDB and non-EDB groups in U.S. EDs. Only full-text English-language articles were included. Outcomes were mortality and hospital LOS. We used random-effects meta-analysis to compare the outcomes. Heterogeneity was assessed with the I² value while publication bias was assessed via the funnel plot.

We identified 3139 studies and included 17, comprising 407,178 ED patients: 194,814 (48 %) EDB and 212,364 (52 %) non-EDB. 87.4 % of patients came from urban academic Emergency Departments with a resuscitation unit or team. Median ED LOS was 6.5 h (IQR 5.18-8.1) for EDB and 4.2 h (IQR 2.38-5.75) for non-EDB (p < 0.01). EDB patients had similar all-cause mortality (OR 1.06, 95 % CI 0.94-1.19, I² = 69 %, p = 0.38) and hospital LOS (mean difference 0.38 days, 95 % CI -0.75-1.50, I² = 61 %, p = 0.51). Funnel plot suggested publication bias favoring higher mortality in EDB.

Our SR/MA suggested that EDB was associated with a non-statistically significant increase in mortality and hospital LOS compared to non-EDB. High heterogeneity and inconsistent boarding definitions were also noted.