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

Objective: To describe and identify the relationship between ED length of stay (LOS) and mortality after ICU admission. Methods: 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 >= 8 h. Univariate and multivariate analyses were performed. Results: 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 >= 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). Conclusion: 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.