Could ambulance diversion affect high-risk patients more?

• Emergencies / First Aid • • Public Health • Jun 24, 10

The elderly, the uninsured and the critically ill are among the groups most likely to rely on an ambulance to get to the hospital, a new study finds—raising the possibility that such high-risk patients are the ones most affected when hospitals turn ambulances away due to emergency room overcrowding.

To help relieve overburdened ERs, hospitals across the U.S. rely on a practice called ambulance diversion—temporarily directing incoming ambulances to other medical centers.

The policy has come under criticism for potentially putting patients at risk by increasing their transit time to the hospital. On the other hand, the goal of the practice is to get patients the treatment they need more quickly—since ER overcrowding may delay the care of both newly arriving patients and the ones already waiting.

Little is known, however, about how ambulance diversion affects the quality of ER patients’ care, or whether certain groups of people may be disproportionately affected by diversions.

For the new study, published in the Annals of Emergency Medicine, researchers used national data on nearly 200,000 ER admissions from 1997 through 2005 to see whether certain groups of Americans rely more heavily on ambulance transport to get to the hospital.

In theory, the researchers reasoned, these same individuals could be more affected by ambulance-diversion policies.

Overall, the study found, Medicare patients, the elderly (those age 75 and older), and the uninsured and publicly insured were among those most likely to use ambulance transport. Not surprisingly, the critically ill relied on ambulances more often than non-critical patients did—at 57 percent, versus 15 percent.

Across all admissions, one-third of Medicare patients used an ambulance, compared with 11 percent of the privately insured. And among the critically ill, 61 percent of Medicare patients were transported by ambulance, versus 47 percent of the privately insured.

Critically ill patients on public insurance or without insurance were similarly more likely to use an ambulance than privately insured patients were. The rate of ambulance transport was also high among the oldest critically ill patients, at 67 percent, as well as the

youngest: among 15- to 24-year-olds, 63 percent arrived at the ER by ambulance.

The findings raise the possibility that these same patients, which includes many of those expected to be most ill upon arriving at the ER, are disproportionately affected by ambulance diversions.

However, the study lacked any data to show whether this is the case, according to lead researcher Dr. Benjamin T. Squire, of the Harbor-UCLA Medical Center in Torrance, California.

“To study this would require a regional database with both information on which patients were diverted as well as their outcomes,” Squire told Reuters Health in an email. “I’m not aware of such a database.”

An alternative, he said, would be for researchers to do a “prospective” study—where ER admissions and ambulance diversions in a given region would be followed over time.

Such a study, Squire noted, would be “expensive and time consuming, but in my opinion, very worthwhile.”

Even if certain patients are being disproportionately affected by ambulance diversions, it is unclear whether that could be hindering their care. Squire and his colleagues point out that studies have linked ER overcrowding to poorer-quality care and a higher patient death rates; so being diverted to a less-crowded ER could benefit patients.

Some studies have found an association between ambulance diversion and delays to see an ER doctor, Squire noted. However, he added, it is unclear whether the delays were due to ambulance diversion, per se, or some other factor in the system—such as regional ambulance services being over stretched.

Despite these open questions, concerns about the potential consequence of ambulance diversion have led to some efforts to curb the practice.

Some systems, Squire noted, have tried to eliminate ambulance diversion altogether. And last year, Massachusetts became the first U.S. state to ban the practice.

Other tactics, Squire said, have included moves to make it more difficult for ERs to divert ambulances, or to penalize them for doing so. Hospitals may, for instance, have to halt all scheduled admissions and elective procedures while they are “on diversion”—a major financial disincentive.

However, Squire pointed out, since the current study suggests that many patients arriving by ambulance are covered by Medicare, the practice of ambulance diversion may well already be costing hospitals money.

SOURCE: http://link.reuters.com/ryt83m Annals of Emergency Medicine, online June 16, 2010.