Is a Prolonged Emergency Department Stay a Risk for Patient Safety?

Objectives: The emergency department (ED) length of stay (EDLOS) has been studied as a metric for ED crowding, as well as an individual risk factor for patient outcomes. Although the results from prior studies vary, larger studies seem to show an association between a prolonged EDLOS and increased adverse events. We aimed to determine how a prolonged EDLOS impacts short-term mortality and to concurrently study these outcomes in different ED occupancy situations. Methods: A retrospective, single-center cohort study was conducted in the Tampere University Hospital ED, Finland. The study sample included 58,440 ED visits leading to hospital admission between January 2018 and February 2020. The main outcome measure was 10-day all-cause mortality in relation to each hour spent in the ED. Various potential confounding factors were taken into consideration, including patient-specific and ED performance-related variables. Patients were divided into 2 subgroups based on whether they were exposed to crowding during the ED stay or not, with crowding defined as the ED occupancy ratio exceeding 90%. Results: The 10-day mortality rate was 1.6% (n = 938). A prolonged EDLOS was not associated with mortality in adjusted logistic regression analyses (odds ratio for 1-hour increase in EDLOS, 1.01; 95% CI, 0.99-1.04). Examining the crowded and noncrowded subgroups did not change the findings. Conclusion: In a Finnish tertiary hospital, a prolonged EDLOS was not an individual risk factor for increased 10-day mortality despite adjusting for confounding factors and considering the possible crowding status of the ED.