Decreasing length of stay in the emergency department with a split emergency severity index 3 patient flow model

There has been a steady increase in emergency department (ED) patient volume and wait times. The desire to maintain or decrease costs while improving throughput requires novel approaches to patient flow. The break-out session "Interventions to Improve the Timeliness of Emergency Care" at the June 2011 Academic Emergency Medicine consensus conference "Interventions to Assure Quality in the Crowded Emergency Department" posed the challenge for more research of the split Emergency Severity Index (ESI) 3 patient flow model. A split ESI 3 patient flow model divides high-variability ESI 3 patients from low-variability ESI 3 patients. The study objective was to determine the effect of implementing a split ESI 3 flow model has on patient length of stay (LOS) for discharged patients.

This was a retrospective chart review at an urban academic ED seeing over 70,000 adult patients a year. Cases consisted of adults who presented from 9 a.m. to 11 p.m. from June 1, 2011, to December 31, 2011, and were discharged. Controls were patients who presented on the same times and days, but in 2010. Visit descriptors included age, race, sex, ESI score, and first diagnosis. The first diagnosis was coded based on methods used by the Agency for Healthcare Research and Quality to codify International Classification of Diseases, ninth version, into disease groups. Linear models compared log-transformed LOS for cases and controls. A front-end ED redesign involved creating guidelines to split ESI 3 patients into low and high variability, a hybrid sort/triage registered nurse, an intake area consisting of an internal results waiting room, and a treatment area for patients after initial assessment. The previous low-acuity area (ESI 4s and 5s) began to see low-variability ESI 3 patients as well. This was done without additional beds. The intake area was staffed with an attending emergency physician (EP), a physician assistant (PA), three nurses, two medical technicians, and a scribe.

There was a 5.9% decrease, from 2.58 to 2.43 hours, in the geometric mean of LOS for discharged patients from 2010 to 2011 (95% confidence interval CI = 4.5% to 7.2%; 2010, n = 20,215; 2011, n = 20,653). Abdominal pain was the most common diagnostic grouping (2010, n = 2,484; 2011, n = 2,464) with a reduction in LOS of 12.9%, from 4.37 to 3.8 hours (95% CI = 10.3% to 15.3%).

A split ESI 3 patient flow model improves door-to-discharge LOS in the ED.