A new study on hospital quality in Pennsylvania argues that patients have a better chance of surviving surgery when their hospital employs a higher percentage of registered nurses trained in bachelor's degree programs.

The study's conclusions, published today in the Journal of the American Medical Association, are controversial among nurses because most enter the profession with degrees from community colleges or hospital diploma programs. Many go on to earn bachelor's degrees, but others don't go back to school.

While the study endorses the bachelor's degree as the best path for producing quality nurses, the point of the research is not to worry patients about the care they receive in hospitals with few baccalaureate-trained nurses, said study author Linda Aiken, a professor of nursing at the University of Pennsylvania. The study shows an association between factors, but doesn't prove that one caused the other.

Good nurses can come from any of the three training routes, Aiken said, but those with bachelor's degrees might be better at detecting patient problems earlier and alerting doctors and other hospital workers. Whatever the explanation, the results should persuade the government and hospitals to financially support expanded education opportunities for nurses, the researchers said.

"The conventional wisdom that a nurse's education doesn't matter -- it's only the nurse's experience -- is really not true," Aiken said. "That's not to say nurses without a bachelor's degree are not perfectly good nurses, but health care is getting more and more complex. For the future, this research suggests there should be progress toward moving the education of nurses up, as it has been in all the other health professions."

The study examined the outcomes for 232,342 surgery patients discharged from 168 hospitals in Pennsylvania between April 1, 1998 and Nov. 30, 1999. Researchers then linked that information with administrative and survey data about nurses at each hospital.

The researchers found that with every 10 percent increase in the proportion of nurses holding a bachelor's degree there was a 5 percent decrease in the likelihood of death within 30 days of admission.

Based on that finding, the researchers estimated that the odds of 30-day mortality and deaths from complications would be 19 percent lower in hospitals where 60 percent of the nurses had at least bachelor's degrees than in hospitals where only 20 percent of the nurses did. That would translate into four lives saved for every 1,000 patients undergoing common surgeries in hospitals with the higher percentage of baccalaureate-trained nurses.

Among hospitals studied, the proportion of hospital nurses holding a bachelor's degree or higher ranged from 0 percent to 77 percent.

Directors of hospital diploma and community college programs said they have lots of questions about the methods used in the study. Some of the results seem counter-intuitive, said Joanne Sperry, director of the Mercy Hospital School of Nursing.

"This same study did not show any difference in outcomes based on experience and that made me really very concerned about the overall results of the study," she said. "It's very clear that the more experience a nurse has, the better the outcomes have to be for patients."