By Lisa Rapaport

(Reuters Health) – Even when patients live in the same communities, and close to the same hospitals, there are small racial and ethnic differences in where they’re taken by ambulance crews, a U.S. study suggests.

Researchers examined data on 864,750 Medicare enrollees who had emergency room visits from 2006 to 2012, including 458,701 cases when patients were transported to the ER by emergency medical services (EMS).

While 61.5% of white patients who used ambulances went to the most frequently visited ER in their zip code, this rate was 5.3 percentage points lower for black patients and 2.5 percentage points lower for Hispanic patients, the study found. The most frequently used ER also tended to be closest to home for many patients, suggesting that more black and Hispanic patients might be bypassing their local ER for a longer ambulance ride to get someplace else, the study team notes.

“A sizable proportion of all EMS transports are not to the nearest ED, and this proportion is even larger among racial/ethnic minorities,” said Amresh Hanchate, lead author of the study and a researcher at Boston University School of Medicine.

Minorities in the U.S. often have worse healthcare outcomes, and the current findings offer fresh evidence of the potential for disparities in care to start before patients ever reach the hospital, the study team writes in JAMA Network Open.

National guidelines require ambulances to take patients to the nearest suitable hospital for the nature of their illness or injury. But this doesn’t always happen, and some previous research suggests that longer transit times and transport to lower-quality hospitals farther from home can contribute to worse patient outcomes.

In the current study, the biggest racial disparities in ambulance destinations happened in urban areas with multiple emergency rooms and hospitals in close proximity, researchers found. Black and Hispanic patients were more likely to be transported to a safety-net hospital than their white counterparts living in the same zip code.

This suggests that differences in transportation destinations may be motivated by factors other than proximity or time, the study authors conclude.

It’s possible that patient and family choice might play a role in where ambulances go, with requests to be taken to the hospital where the patient receives care for other conditions explaining some of the differences, they note. This is supported by the fact that disparities were similar when the researchers looked at ER “walk-in” patients who did not take an ambulance to the hospital.

It’s also possible that some patients in ambulances bypassed the closest hospital because they required specialty services that were only available at a trauma center farther way.

The study didn’t examine whether patient outcomes differed based on hospital choice.

“The cause for this observed pattern is unknown and needs to be further studied to really understand the impact on patient clinical outcomes and if such outcomes vary by race and ethnicity,” Hanchate said “We need more research to understand the role that patient choice, usual source of care and clinical condition play in guiding EMS transportation decisions in diverse systems across the United States.”

SOURCE: JAMA Network Open, online September 6, 2019.