The findings, from David Chang and colleagues at the University of California, San Diego, are based on 12 years of hospital data from their state, covering 47,000 injured kids and teens.
"We suspect that there's something about the system, and it could be the diversity or it could be the health care system in California, where there's less of a difference between races than you see in different parts of the country," Chang told Reuters Health.
California's ethnic diversity may allow for more "culturally competent care" that ultimately improves outcomes for minority patients, he and his colleagues said.
According to findings they published in the Archives of Surgery, falls, car crashes and gun accidents were among the causes of kids' injuries - with guns injuring a disproportionate number of black kids and falls happening more often in Asians.
Deaths originally seemed to be slightly less common in white kids than in blacks and Hispanics, but those differences disappeared when the researchers accounted for age, mechanism of injury and an estimate of injury severity.
In that analysis, Asian children were less likely to die from injuries than youths of other races and ethnicities.
Past research has found racial disparities in many areas of health care, including in treatment outcomes for adults who are sent to the hospital with a serious injury.
Some experts have also seen that pattern in younger patients, including Dr. Richard Falcone, head of trauma services at Cincinnati Children's Hospital Medical Center, who wasn't involved in the new study.
"Even though they all come here so they all have access to the same trauma center, we do see some differences in outcomes, probably due to insurance status in the end," he said.
Kids who don't have health insurance before arriving at the hospital may have gone a longer time without seeing a pediatrician for a check-up, or they may have more social stressors, he said. Both of those could affect how well they respond to treatment.
Still, Chang and his colleagues said, insurance status tends to be less of an issue in children because of the greater number of government-run programs available. And children wouldn't yet have developed the type of chronic health problems that are more common in minorities and the poor than the white and well off.
Falcone agreed with Chang that California's diversity could explain some of the differences between research conducted there and in different parts of the country.
"There are studies out there showing the more culturally competent, or the more diverse your community, the less likely you are to see some of these disparities," he told Reuters Health.
Falcone said future studies could try to tease apart how much diversity influences differences in outcomes by race, and what else is different between more and less diverse states that could affect minority health.
Until then, Chang added, all medical schools can teach cultural competency - whether or not they're in diverse states.
SOURCE: http://bit.ly/R2Va0C Archives of Surgery, online September 17, 2012.