The chances of surviving a gunshot or a car crash may vary across North America, researchers have found, suggesting room for improvement in some healthcare systems.

Based on data from six U.S. and three Canadian sites, the researchers estimate that there are more than 125,000 severe traumatic injuries in North America every year.

They found survival rates ranged from about 40 to 80 percent, with two Canadian cities -- Vancouver and Toronto -- at either end of the spectrum.

Traumatic injury is an important health problem, said Dr. Graham Nichol, of the University of Washington in Seattle, who worked on the study. And we can do better.

During one year, the researchers found more than 7,000 severe injuries, with falls and car accidents the most common ones.

Based on reports from emergency rescuers, there were about 34 injuries per 100,000 people on average and less than 9 deaths, but the rates varied considerably from place to place.

The site with the highest injury rate (95 per 100,000) was Seattle-King County, while Alabama had the highest death rate (29 per 100,000).

The researchers, whose findings appear in the Annals of Surgery, were unable to tease out the reasons for the large regional variation, however.

It's alarming to see these differences, said Dr. Roger Hartl, an expert in brain injuries at Weill Cornell Medical College in New York City, who was not involved in the study.

I'm sure part of this may be due to inadequate treatment, he said, adding that an earlier standardization of the treatment of brain injury in the U.S. had more than halved the death rate from that type of injury. But it is hard to say anything else at this point.

He stressed that the patients couldn't necessarily be compared between the different sites and said it was hard to know if changing care would improve outcomes for injuries overall.

It is an incredibly difficult task to interpret these data, Hartl told Reuters Health.

SOURCE: Annals of Surgery, July, 2010.