KANSAS CITY, Mo. -- Black hospital patients are far less likely to survive cardiac arrest than white patients, new research shows.

And the reason in many cases is that black patients usually go to the hospitals that do the poorest job resuscitating patients.

Just 25.2 percent of black patients who suffered cardiac arrest while they were hospitalized left the hospital alive, according to a study published this week in The Journal of the American Medical Association. That compares with 37.4 percent of white patients who survived -- a difference of 48 percent.

"That's huge -- larger than any other survival gap by race," said Paul Chan, a researcher at St. Luke's Hospital in Kansas City, Mo., who led the national study. "And it's poignant because the white survival rate wasn't very high either."

Many studies have found racial disparities in the quality of health care. Black and Hispanic preschoolers are less likely to receive routine asthma medications than are white children. Minority residents of nursing homes are less likely to get glasses or hearing aids than are white residents. Minority women wait twice as long as white women for follow-up tests after an abnormal mammogram.

The reasons for such disparities have been hard to pin down. Doctors may not be giving minorities equal care. Poverty and social circumstances may make health care less accessible. Cultural differences may influence when patients seek care. Chan decided to examine racial disparities in cardiac arrest care among patients who were already in the hospital because their treatment would be less affected by economic and cultural factors.

During cardiac arrest, the heart stops pumping blood to the body; survival depends on immediate resuscitation. "With cardiac arrest, time is of the essence. It's measured in seconds, not days or weeks," Chan said. "These other (cultural and economic) things should play a very little role."

He collaborated with other researchers at St. Luke's and at Yale and Duke universities, and the universities of Washington and Michigan. They looked at data on 10,011 patients at 274 hospitals from 2000 to 2008.

The researchers found that doctors treated black patients as aggressively as white patients, giving their hearts virtually the same number of electric shocks and spending the same amount of time on resuscitation.

Black patients tended to enter the hospital sicker, with more kidney disease, diabetes and other maladies than did white patients. But their poorer health accounted for only about 30 percent of the difference in survival rates, Chan said.