NEW YORK (Reuters Health) - Many of the people most likely to need trauma care -- including the poor and minorities -- might find themselves furthest from hospitals that can provide it, suggests new research.

Trauma centers are emergency departments equipped to provide a higher level of care than the average ER for a traumatic injury, such as a gunshot or stab wound.

"As an emergency physician who has worked in a number of ERs, both trauma facilities and non-trauma facilities, I know that trauma center care really does make a difference," lead researcher Dr. Renee Hsia of the University of California, San Francisco, told Reuters Health in an e-mail.

When caring for a traumatic injury, she added, "minutes matter."

Previous studies have confirmed what may not come as a surprise: rural patients usually have to travel further than urban patients to reach such care. Researchers had not looked beyond distance, however, to see what other factors might influence access.

In the new study, Hsia and her colleague Yu-Chu Shen investigated the location of trauma centers in relationship to traditionally vulnerable patients.

In both urban and rural areas, "certain disadvantaged groups have been shown to be at higher risk for injury," the authors note, "and at the same time, certain racial/ethnic groups have been shown to have poorer outcomes."

They linked data from the American Hospital Association's 2005 Annual Survey with zip code-based information from the U.S. Census, covering an estimated 265 million residents. "Easy" access to a trauma care was defined as living within a 20-minute drive; "difficult" meant the nearest center was more than 60 minutes away.

Overall, the findings suggested that about 38 million people in the U.S. live at least an hour from a trauma center.

Two out of every three urban communities had relatively easy access to trauma centers, while 12 percent faced difficult distances, report the researchers in the Archives of Surgery. In the rural setting, the same figures were 24 and 31 percent.

Although differences between urban and rural areas in degree of access may have been expected, the disparities within each were somewhat less so.

The researchers found that urban communities with a large foreign-born contingent, for example, faced up to twice the odds of having difficult access to trauma care compared to populations with predominantly U.S.-born residents.

Similarly, a high proportion of African American residents raised the odds of difficult access for an urban or rural community by about a third, and a large number of poor families living at or below the poverty line increased the odds by two-thirds.

Hsia noted that these same vulnerable populations also tend to be the most frequently hospitalized for traumatic injuries.

"This means that those who need the services most are further away from them," she said.

Moreover, while population size continues to rise, bringing with it increased demand for emergency services, emergency departments and trauma centers continue to close across the country due in part to financial hardships, noted Hsia.

The researchers point out that knowledge of this mismatch in the supply and demand for trauma centers could help healthcare policymakers reach better informed decisions.

"Trauma care isn't a luxury good -- it's not like Botox, or plastic surgery," Hsia said. "Having access to trauma care means someone lives or dies based on whether they get it or not."

SOURCE: Archives of Surgery, online January 17, 2010.