A multi-institutional study focused on California says that hospitals in areas with large minority populations are more likely to be overcrowded and to divert ambulances, delaying timely emergency care.
The researchers examined ambulance diversion in more than 200 hospitals around the state to assess whether overcrowding in emergency rooms disproportionately affects racial and ethnic minorities. They found that minorities are more at risk of being impacted by ER crowding and by diversion than non-minorities.
The study will be published in the August issue of Health Affairs.
"Our findings show a fundamental mismatch in supply and demand of emergency services,'' said lead author Renee Y. Hsia, MD, assistant professor of emergency medicine at UCSF. She is also an attending physician in the emergency department at San Francisco General Hospital & Trauma Center.
"If you pass by a closer hospital that is on diversion for a hospital 15 minutes down the road, you are increasing the amount of time the patient is in a compromised situation," Hsia said. "It puts these patients at higher risk for bad health outcomes from conditions like heart attacks or stroke, where minutes could mean the difference between life and death."
Ambulance diversion is triggered when a hospital's emergency department is too busy to accept new patients - ambulances are rerouted to the next available ER, sometimes miles away. It is especially common in urban areas, particularly in recent years as demand for emergency care has risen.
This is the first study using hospital-level data to show how diversion affects minorities, the authors said.
The scientists looked at emergency departments in all of California's acute, nonfederal hospitals operating in 2007. Pediatric hospitals were excluded because they typically do not treat adults, as well as hospitals in counties that forbid the practice of ambulance diversion. Altogether, the study involved 202 hospitals in 20 counties where diversion is permitted - the majority of them are not-for-profit facilities.
In all, 92 percent of the hospitals were on diversion for a median of 374 hours over the course of the year. Those serving high numbers of minorities were on ambulance diversion for 306 hours compared to 75 hours at hospitals with fewer minority patients.
"Because ambulances typically transport patients needing true emergency care, diversion reroutes the neediest patients away from their nearest hospital, representing a failure of the systems to provide the intended care,'' the authors wrote.
Some limitations to the study were noted: Diversion is an imperfect measure of overcrowding, and even when an emergency department is on diversion status, certain patients - particularly trauma patients - still can be accepted. Additionally, the study looked solely at California hospitals.
"Emergency departments and trauma centers are closing more frequently in areas with vulnerable populations, including racial and ethnic minorities,'' Hsia said. "This is a systems-level health disparities issue that requires changing the 'upstream' determinants of access to emergency care. It's not just a problem at the level of the emergency department itself, but of the hospital and entire system."
The authors say their research points to the need for systemic reform, including better management of hospital flow and statewide criteria regulating diversion policies.