Emergency Department Crowding: Factors Influencing Flow

Background: The objective of this study was to evaluate those factors, both intrinsic and extrinsic to the emergency department (ED) that influence two specific components of throughput: “door-to-doctor” time and dwell time. Methods: We used a prospective observational study design to determine the variables that played a significant role in determining ED flow. All adult patients seen or waiting to be seen in the ED were observed at 8pm (Monday-Friday) during a three-month period. Variables measured included daily ED volume, patient acuity, staffing, ED occupancy, daily admissions, ED boarder volume, hospital volume, and intensive care unit volume. Both log-rank tests and time-to-wait (survival) proportional-hazard regression models were fitted to determine which variables were most significant in predicting “door-to-doctor” and dwell times, with full account of the censoring for some patients. Results: We captured 1,543 patients during our study period, representing 27% of total daily volume. The ED operated at an average of 85% capacity (61–102%) with an average of 27% boarding. Median “door-to-doctor” time was 1.8 hours, with the biggest influence being triage category, day of the week, and ED occupancy. Median dwell time was 5.5 hours with similar variable influences. Conclusion: The largest contributors to decreased patient flow through the ED at our institution were triage category, ED occupancy, and day of the week. Although the statistically significant factors influencing patient throughput at our institution involve problems with inflow, an increase in ED occupancy could be due to substantial outflow obstruction and may indicate the necessity for increased capacity both within the ED and hospital.

[1]  D. Kleinbaum,et al.  Survival Analysis: A Self-Learning Text. , 1996 .

[2]  David G. Kleinbaum,et al.  Survival Analysis: A Self-Learning Text , 1997 .

[3]  R. Salluzzo,et al.  Variables That Affect Patient Throughput Times in an Academic Emergency Department , 1997, American journal of medical quality : the official journal of the American College of Medical Quality.

[4]  Nina S. Parikh,et al.  Emergency department use in New York City: a substitute for primary care? , 2000, Issue brief.

[5]  J. Richards,et al.  Overcrowding in the nation's emergency departments: complex causes and disturbing effects. , 2000, Annals of emergency medicine.

[6]  R. Derlet,et al.  Overcrowding in emergency departments: increased demand and decreased capacity. , 2002, Annals of emergency medicine.

[7]  George Wells,et al.  The effect of hospital occupancy on emergency department length of stay and patient disposition. , 2003, Academic emergency medicine : official journal of the Society for Academic Emergency Medicine.

[8]  S. Schneider,et al.  Emergency department crowding: a point in time. , 2003, Annals of emergency medicine.

[9]  Linda R Brewster,et al.  Does U.S. hospital capacity need to be expanded? , 2003, Health affairs.

[10]  S. Trzeciak,et al.  Emergency department overcrowding in the United States: an emerging threat to patient safety and public health , 2003, Emergency medicine journal : EMJ.

[11]  Peter Cunningham,et al.  Insured Americans drive surge in emergency department visits. , 2003, Issue brief.

[12]  L. McCaig,et al.  National Hospital Ambulatory Medical Care Survey: 2000 Emergency Department Summary , 2002 .

[13]  David A Thompson,et al.  Emergency department triage: why we need a research agenda. , 2005, Annals of emergency medicine.

[14]  Steven Asch,et al.  Effects of hospital closures and hospital characteristics on emergency department ambulance diversion, Los Angeles County, 1998 to 2004. , 2006, Annals of emergency medicine.

[15]  J. Greene,et al.  Emergency department flow and the boarded patient: how to get admitted patients upstairs. , 2007, Annals of emergency medicine.

[16]  D. Aronsky,et al.  Measuring and forecasting emergency department crowding in real time. , 2007, Annals of emergency medicine.

[17]  Alex Kiss,et al.  The effect of low-complexity patients on emergency department waiting times. , 2007, Annals of emergency medicine.

[18]  Sanjeev K. Bordoloi,et al.  Improving operational efficiency in an inner-city emergency department , 2007, Health services management research.

[19]  David C Pate,et al.  Special report: quality of care survey. Improving patient flow. , 2007, Physician executive.

[20]  William Martin.  Special report: quality of care survey. Quality models: selecting the best model to deliver results. , 2007, Physician executive.

[21]  N. Rathlev,et al.  Time series analysis of variables associated with daily mean emergency department length of stay. , 2007, Annals of emergency medicine.