One Ambulance Per Minute Diverted in U.S., Study Finds

ATLANTA, Feb. 6 -- An ambulance is diverted to a different hospital every minute, on average, because emergency rooms in the United States are so overcrowded, suggests one of the first national studies of the issue.

The study did not measure how the delays in getting to hospitals affected patients' survival, but the study's lead author said it could not have been for the better.

"Most of the people that arrive by ambulance are older, and they have more serious medical conditions," said Catharine Burt of the National Center for Health Statistics.

"So the fact that they're being delayed . . . whether it's two minutes or five minutes or 15 . . . I can only assume that's going to have some impact," she said.

About half a million ambulances were diverted from their original destinations because the receiving hospitals' emergency departments were too crowded, the survey data from 2003 indicated. The study, released Monday, is being published in the journal Annals of Emergency Medicine.

An ambulance diversion occurs when a hospital emergency department closes its doors to incoming ambulances and directs traffic to other hospitals. Often, diversions occur because a hospital's ER is overcrowded or the hospital has a shortage of critical-care beds.

The problem is not new. But most previous reports were "based on just a few cities complaining bitterly about the problem. We didn't know the national impact," Burt said.

The findings come from responses from 405 U.S. hospital emergency departments, about 10 percent of U.S. hospital ERs, Burt said.

The researchers based their estimates on the amount of time hospitals reported being on diversion and the number of ambulance arrivals during those periods. They did not count how many times ambulance drivers said they were diverted.

Air and ground ambulances brought in about 14 percent of ER patient traffic that year, the researchers found.

About 16.2 million patients arrived by ambulance to all emergency departments, and 70 percent had urgent conditions that required care within an hour. More than 60 percent were 45 or older, and almost 40 percent were 65 or older, researchers said.

Ambulance diversions sometimes produce a chain reaction -- particularly in larger cities, where the problem is most often reported. That effect was documented in a companion study that found ambulance diversions at Los Angeles County, Calif., hospitals more than tripled between 1998 and 2004.

"This suggests that when a hospital decides to go on diversion, nearby hospitals subsequently go on diversion as they become overwhelmed by the increase in incoming ambulance transports," Benjamin Sun, that study's lead author, said in a statement.

"Around Atlanta, diversions are a regular thing," said Denise Simpson, a spokeswoman for Grady Memorial Hospital, which operates the city's busiest ER and trauma center.

Burt said data for 2004, which have not been published, showed the diversions occurred at about the same rate. But hospitals have been working on increasing capacity in the past three years, and it is possible the national situation has improved since then, she added.