The Effect of Emergency Department Expansion on the Emergency Department Length of Stay in a Tertiary Hospital

ABSTRACT

PURPOSE: In this study, we aimed to measure the effects of emergency department (ED) expansion at a tertiary hospital on overall ED length of stay (LOS). METHODS: This study was a before and after study using data from a tertiary medical center in Seoul, a large metropolis. We used electronic medical records and administrative databases obtained from the ED. The control period (before expansion) was defined as from January 1 to April 31, 2016. The study period (after expansion) was defined as from May 1 to August 31, 2016. The number of ED beds increased from 42 to 74 after the expansion. After adjusting individual characteristics and institutional characteristics, multivariate regression analysis was carried out to evaluate the effects of expansion on overall ED LOS. RESULTS: A total of 45,632 patients visited the emergency medical center 20,592 patients before and 25,040 after the expansion. Although the absolute number of patients increased, the portion of medical patients, portion of non-referral patients, and ambulatory patients decreased during the study period (all p<0.001). Average visit number increased from 170.2 (standard deviation [SD], 27.3) to 203.6 (SD, 21.3) (p<0.001). The overall ED LOS increased from 332.2 (SD, 473.4) to 391.0 minutes (SD, 649.5). After adjusting for potential confounders, we found that ED expansion was associated with an increase in ED LOS by 75.8 minutes (95% confidence interval, 63.5 to 88.2). CONCLUSION: We found that the ED expansion was associated with a significant increase in ED LOS.