New America's Dr. Guy Clifton and Hannah Graff this week posted a new issue brief on ambulance diversions—when hospital Emergency Departments can't handle more patients and divert ambulances elsewhere. Yesterday we wrote about how common diversions are, and how they can affect anyone, regardless of whether they have good, bad or no health insurance. Today we'd like to talk about three reasons why diversions happen, and what they say about the troubled state of our health care system. If you've been following our earlier posts on emergency room crowding, you'll know that the problem is not just the uninsured.

• Emergency Departments have become a major source of primary care. The New England Healthcare Institute has found that one-in-four emergency room visits were non-urgent, and another fourth could have been addressed or prevented by a visit to a doctor's office. Uninsured people are twice as likely to seek care for a chronic condition in an ED, when it could be (and should be) treated in a primary care setting. Misuse of EDs makes it more likely that a hospital will have to divert ambulances.

• The number of patients that can be admitted to an ED in a given hospital is dictated by the number of staffed beds, or beds attended to by hospital staff on duty. No available staff means no room for emergency patients. Hospitals will ask that ambulances be diverted if their own staff is occupied and unable to give prompt care for new arrivals. Lack of staffed beds tends to be a problem in urban hospitals with a high volume of patients. (A hospital can have more licensed beds than staffed beds)

• Inefficient patient flow. This refers to how hospitals manage their own resources, how and when they discharge patients, how and when they move patients from one setting (such as the ED) to another (a regular floor or an ICU for instance). According to the GAO, half of hospitals reported one reason they go on diversion is when they have ED patients who need to be moved elsewhere in the hospital—but they don't have a suitable bed open. This graph illustrates that "patient flow" is indeed a major problem.

Conditions Hospitals Reported as Contributing to Diversion, FY2001

Source: General Accounting Office, “Hospital Emergency Departments: Crowded Conditions Vary among Hospitals and Communities,” 2003.

On Monday we'll wrap up this series with some thoughts on what we can do to solve the problem.