Diversions worsening, trend may continue

ED managers must be proactive to reduce hours

Two studies to be published in the April 2006 edition of Annals of Emergency Medicine1,2 indicate that the ambulance diversion problem in America has become even more serious — and is growing steadily worse.

Centers for Disease Control and Prevention (CDC) researchers, in the first national study of ambulance diversions, found about one ambulance every minute in the United States is diverted from its originally intended ED because it was overcrowded and could not safely care for another sick or injured patient. The research is based on the 2003 National Hospital Ambulatory Medical Care Survey, an annual probability sample survey of U.S. hospital EDs and outpatient departments.

"I think the trends with ambulance diversion are concerning and indicate the capacity problems we see in hospitals aren’t going away," says Brent Asplin, MD, MPH, the journal’s editor for the CDC study, department head of emergency medicine at Region’s Hospital St. Paul (MN), and professor of emergency medicine at the University of Minnesota.

In the second study, which examined the impact of hospital closures and hospital characteristics on ambulance diversions, University of California-Los Angeles (UCLA) researchers looked at ambulance diversion hours for hospitals in Los Angeles County over a seven-year period. The study found that ambulance diversions at Los Angeles County hospitals more than tripled between 1998 and 2004.

"We were surprised by the magnitude in the increase of diversion hours," says Benjamin C. Sun, MD, MPP, the lead author of the UCLA study. "By 2004, diversions represented 25% of the total operating hours of the average ED."

ED managers not helpless

While many of the forces contributing to diversion, such as hospital closings, may be beyond the control of ED managers, Asplin and Sun say there is much they can do to improve the situation within their own facilities.

"Rule No. 1 is not to try to solve your hospital’s capacity problems with an ED-based initiative," Asplin advises. "Diversions are clearly tied to capacity constraints across the hospital."

In addition, he says, ED managers must do a much better job of embracing evidence-based operations. "That means having a much more sophisticated approach to understanding patient flow, measuring key indicators, and having a system built that eliminates bottlenecks," Asplin says. "Just as you wouldn’t think of treating a heart attack patient without doing an EKG, you can’t solve patient flow problems without access to real-time data about patient flow across the hospital."

For example, one of the biggest drivers for capacity problems in the ED is the elective admission schedule — particularly from the operating room, he says. "Logically, there may be sudden surges in emergency admissions, but in most hospitals it’s easier to predict in the ED than demands coming from the OR," Asplin notes.

While the problems may be hospitalwide, the ED manager still can provide the impetus for improvement, he says. "If you feel as the ED director that you have done all you can do, and every time you make improvements on the front end you still get overwhelmed because inpatients are waiting longer to get upstairs, it’s your job as ED manager to get hospital leadership engaged in improving real-time management of flow," he says.

There are several resources for ED managers seeking to learn more about the science of patient flow, says Asplin. "The Institute for Healthcare Improvement has a whole collaborative on flow and is beginning a new one on EDs."

In addition, there are a lot more initiatives coming from the hospital industry and from emergency medicine professional groups such as the American College of Emergency Physicians.

Sun agrees that diversion is a hospitalwide problem. Still, he says, "there are things you can do that are operational in nature, like decreasing door-to-doc times. However, the major impact will be felt by freeing up beds being occupied by inpatients."

He advises ED managers to work closely with the hospital management "to make clear this is a patient safety issue." How do diversions affect patient safety? "If a patient is used to getting all their care at your hospital and they are now sent somewhere else, there is first of all a delay in their getting treated by a physician," he says. "In addition, that treating physician will not know anything about the patient."

The ED manager also can point out the financial impact of diversions, says Sun. "Depending on your insurance mix, you may be losing potential revenue."


  1. Sun BC, Mohanty S, Weiss R, et al. Effects of hospital closures and hospital characteristics of Emergency Department ambulance diversion, Los Angeles County, 1998-2004. Ann Emerg Med 2006; 47:in press.
  2. Burt CW, McCraig LF, Valverde RH. Analysis of ambulance transports and diversions among U.S. emergency departments. Ann Emerg Med 2006; 47:in press.


For more information on reducing diversion hours, contact:

  • Brent Asplin, MD, MPH, Department of Emergency Medicine, Region’s Hospital St. Paul (MN). Phone: (651) 254-3044.
  • Benjamin C. Sun, MD, MPP, University of California-Los Angeles Medical Center, Los Angeles. Phone: (310) 903-3177.

For more information on Institute for Healthcare Improvement collaboratives to improve ED operations, go to the IHI web site: www.ihi.org/ihi. Scroll down the center column and click on "Emergency Department Learning and Innovation Community."