Major cities often safest places in the U.S.

The new study, which appears online ahead of print in the Annals of Emergency Medicine, found that for the entire population, as well as for most age subgroups, the top three causes of death were motor vehicle collisions, firearms, and poisoning. When all types of fatal injuries are considered together, risk of injury-related death was approximately 20 percent lower in urban areas than in the most rural areas of the country.

"Perceptions have long existed that cities were innately more dangerous than areas outside of cities, but our study shows this is not the case" said lead study author, Sage R. Myers, MD, MSCE, assistant professor of Pediatrics, Perelman School of Medicine and attending physician, Department of Emergency Medicine at CHOP. "These findings may lead people who are considering leaving cities for non-urban areas due to safety concerns to re-examine their motivations for moving. And we hope the findings could also lead us to re-evaluate our rural health care system and more appropriately equip it to both prevent and treat the health threats that actually exist."

The study examined county-level data on all injury deaths across the U.S. from 1999-2006 (because of their unusual nature, deaths from the 9-11 terrorist attacks were excluded).

Findings from the study support prior work showing that overall homicide rates are lower in rural areas than urban areas. This was found to be true in all age groups, except the oldest adults (over 65 years old). Suicide rates, on the other hand, showed an increase with rurality, but the increased rate of suicide death in rural areas only reached statistical significance for the two youngest age groups: 0-14 years and 15-19 years.

However, the magnitude of homicide- and suicide-related deaths, even in urban areas, is far outweighed by the magnitude of unintentional-injury deaths -- such as those from car crashes and falls -- in nonurban areas, especially in rural areas. Specifically, the rate of unintentional-injury death is over 15 times that of homicide for the entire population and the risk of unintentional-injury death is 40 percent higher in the nation's most rural counties compared to the most urban.

The research team found that the bulk of unintentional injury deaths result from motor vehicle crashes, with motor vehicle injury-related deaths occurring at a rate that is more than 1.4 times higher than the next leading mechanism of injury death. In rural areas, this difference is even more pronounced, where motor vehicle injury-related death rates are twice that of the next leading injury mechanism. Across the rural-urban continuum, the risk of motor vehicle-related injury death is 2 times more likely in rural areas as compared to the most urban.

"We think our work serves as a reminder that injury is an important health issue for Americans, wherever they live. Our findings can inform both targeted prevention efforts and strategic efforts to improve trauma care in the U.S. This work provides a real opportunity to build systems of medical care that are positioned to best care for the populations that depend upon them for life and limb saving treatment in their time of need," said senior study author, Brendan G. Carr, MD, MSHP, assistant professor Emergency Medicine and Biostatistics and Epidemiology at Penn.

The researchers note that next steps in this line of research should focus on creating local injury priority scores -- a relatively simple and objective tool that uses data available in trauma center registries to rank injury causes according to both frequency and severity -- and considering innovative ways to continue to develop the U.S. emergency and trauma care system to assure that all Americans receive the best emergency and trauma care possible. "Trauma has been a leader in planning for care from the population perspective," says Carr, referencing the interactive trauma system mapping tool created at Penn, "but we've still got work to do."