An Oregon Health & Science University study found that increasing intensive care unit (ICU) bed capacity in hospitals can significantly decrease ambulance diversion and increase monthly net revenues. The study was published online in the Annals of Emergency Medicine.

Ambulance diversion has become routine in many parts of the country, including Oregon, and is widely believed to be a public health concern. The extent to which a hospital is on divert is likely to be correlated with the availability of inpatient beds. This study addresses the economic outcomes of ambulance diversion on hospital finances.

"Hospitals have been reluctant to commit the resources needed to increase ICU beds," said study author K. John McConnell, Ph.D., assistant professor of emergency medicine in the OHSU School of Medicine and an economist in the OHSU Center for Policy & Research in Emergency Medicine. "This study shows not only that increasing beds can decrease ambulance diversion, which is good for patients, but that hospitals can benefit financially as well."

The study analyzed adult, nontrauma patients arriving by ambulance during 2002 and 2003. The OHSU Emergency Department averages 43,000 patients per year, 8,000 of those arriving by ambulance. Visits by ambulance patients resulted in average net revenues and charges that were almost three times higher than those for patients arriving at the emergency department by other means.

During the study period, staffed ICU beds increased from 47 to 67, resulting in a two-thirds decrease in ambulance diversion hours, followed by increased revenues for ambulance patients of approximately $175,000 per month. This represented a 10 percent increase in revenues from ambulance patients.

The study determined that every hour of ambulance diversion cost the hospital approximately $1,100 in revenues, even without including trauma patients who typically generate the highest revenues. This is due in part to the fact that ambulance patients are more likely to be admitted to the hospital and are significantly more likely to be covered by Medicare.

"While the patient benefits and financial gains provide incentives for hospitals to reduce ambulance diversion, these incentives may be only a partial solution," said McConnell. "True relief will probably require support from other areas, such as external financial payments and better regulatory policies concerning emergency departments."