Highlights from SAEM 2002: ED Overcrowding—New Research on an Old Problem

Abstract & Commentary

The following are brief summaries of three abstracts presented recently at the Society for Academic Emergency Medicine 2002 annual meeting in St. Louis.

Source: Asplin BR, et al. Measuring emergency department crowding and hospital capacity. Acad Emerg Med 2002:9;366.

The authors attempt to develop a reproducible measure of emergency department (ED) crowding that correlates with outcomes. Using a prospective method, they collected ED and hospital capacity data at two urban teaching hospitals during eight randomly selected 24-hour periods. Data include ED volume, patient acuity, ED boarding of inpatients, staffed inpatient bed capacity, waiting times to see a physician, and provider ratings of ED crowding using a rating scale. They also recorded ambulance diversion episodes and patients leaving without being seen (LWBS), and then analyzed the correlation between measures of ED crowding and these outcomes. Their analysis showed that two measures correlated with ambulance diversion: ED occupancy and an acuity-adjusted measure of ED census. Three measures correlated with LWBS—ED boarding burden (the percent total ED bed hours used to board inpatients), hospital census, and waiting times to see a physician. The authors conclude that their measures of ED crowding correlate with important outcomes such as ambulance diversion and patients LWBS, and suggest that validation at other sites is required.

Source: Schull MJ, et al: Nurses, patients, and physicians: An analysis of causes of emergency department overcrowding. Acad Emerg Med 2002:9;367.

This study from Toronto defined ED overcrowding as ambulance diversion and used statistical techniques to examine the association between this and nurse hours, physicians on duty, and admitted patients held in the ED. Other variables examined included ambulance, walk-in, and major trauma patient volume; admitted patient volume; average time for assessment and disposition; time of day; and day of week. The study period included 37,999 patients with the following characteristics: 2% were trauma patients, 16% arrived by ambulance, and 22% were admitted. ED nurse hours per eight-hour interval averaged 60, but varied by three-fold. A mean of 3.2 admitted patients were held in the ED each interval. For admitted patients, the time from registration to admission order (assessment time) and from admission order to ED departure (holding time) averaged 5.2 and 3.5 hours, respectively. The authors determined that ED nurse hours and specific physicians on duty were not associated with overcrowding. The number of admitted patients held in the ED (p=< 0.001), number admitted per interval (p=0.04), assessment time (p=0.008), and holding time (p < 0.001) all were associated with overcrowding. Ambulance patients were associated with overcrowding (p < 0.001), but walk-in (p=0.2) and major trauma patients (p=0.4) were not. The authors conclude that, while a minority of patients are admitted, they contribute disproportionately to overcrowding. Furthermore, they observe that reducing the volume of walk-in patients is unlikely to lessen overcrowding.

Source: Richardson DB. Occupancy with inpatients independently predicts decreased ED performance. Acad Emerg Med 2002:9;507.

This Australian study examines the hypothesis that ED occupancy with inpatients interferes with ED function. The author completed a retrospective observational study of all 50,836 presentations to a tertiary ED during 52 weeks in 2000. The ED register was used to determine the number of patients waiting to be seen and the number of patients being seen who required admission at the time of each presentation. The author determined that relative occupancy with inpatients at any time is a negative predictor of ED waiting time performance, independent of the number waiting to be seen— and that performance was affected mainly in the less-urgent triage categories.

Commentary by Richard J. Hamilton, MD, FAAEM, ABMT

Like most ED physicians, I have spent my entire career in emergency medicine considering the issue of overcrowding, from urban university to suburban community hospitals in both New York and Philadelphia. We all have wild theories (full moon) and sociologic considerations (payday Friday). The crisis is worsening, and I know of no ED that is witnessing a decrease in overcrowding, even if its census is the same. Everyone at the table of leadership has an antagonistic theory. Hospital administrators suggest that nurse staffing levels are adequate and appropriate for the annual volume. ED physicians feel nursing staff levels are too low to support an efficient practice, and the nursing staff feel they are stretched to the limit. Everyone is right, and they all are at their wits’ end.

It is exciting to see that research regarding overcrowding finally is gaining momentum. I counted at least a dozen abstracts on that subject at this year’s SAEM meeting. Above are three particularly illustrative, well-conceived, and well-executed studies that I will share with my hospital administration. Each attempts to define overcrowding and how it affects the ED; factors that contribute to overcrowding are identified, and—perhaps most important—other factors that do not contribute to overcrowding are described.

What do the authors find? Boarding patients in the ED is the key determinant for overcrowding. Factors which impact this (e.g., hospital inpatient census) are markers for this particular problem. Prolonged patient evaluation by the ED and admitting services also contribute to overcrowding. When more ambulances arrive, the ED is more likely to become overcrowded. Other, more minor determinants include patients admitted over a narrow time interval. What does not contribute to overcrowding? Which physician is practicing, what the nurse staffing levels are for that particular shift, and how many walk-in patients have registered. A steady, determined effort of precisely identifying the causes of ED overcrowding is the first step in identifying the real problems and their solutions, and in avoiding the misleading misconceptions that only perpetuate the problem. 

Dr. Hamilton, Associate Professor of Emergency Medicine, Program Director, Emergency Medicine, MCP, Hahnemann University, Philadelphia, PA, is on the Editorial Board of Emergency Medicine Alert.