Is ED length of stay before ICU admission related to patient mortality?

To describe and identify the relationship between ED length of stay (LOS) and mortality after ICU admission.

We undertook a retrospective cohort study of records from the Australian and New Zealand Intensive Care Society Adult Patient Database (from 1 January 2000 to 31 December 2006). Data from 45 hospitals and 48 803 ED patients directly transferred to ICU were included. Patients were divided into ED LOS<8 h and ED LOS>or=8 h. Univariate and multivariate analyses were performed.

Median ED LOS was 3.9 h (interquartile range 2.0-6.8). Patients transferred within 8 h (80.9%) were younger (P<0.001) and more seriously ill (higher mortality and mechanical ventilation rate) than those transferred>or=8 h. There was no clear relationship between ED LOS and hospital survival for patients admitted directly to ICU (odds ratio=1.01 per hour, 95% confidence intervals 0.99-1.02).

Although 20% of critically ill patients spend more than 8 h in ED before transfer to ICU, we were unable to demonstrate an adverse relationship between time in ED and hospital mortality.