On education, her paper in 2003 found that every 10% increase in the proportion of nurses with a bachelor's degree was associated with a 4% decline in mortality. Her team looked at hospitals where the proportion of nurses with bachelor's degrees varied from 90% to none, a wide variation throughout the country.
"It was," she says, "myth-busting of the notion, especially in the United States, that doctors need a lot of education ... but nurses didn't really need an education. All they needed was experience."
A big success "was getting the American Organization of Nurse Executives to say that a baccalaureate degree was the preferred educational credential for a hospital nurse." That was followed by the Institute of Medicine report in 2010, which called for 80% of the nursing workforce to have a baccalaureate degree by 2020, up from about 50% today.
Her third issue may be the most challenging: the nursing work environment.
"We found that if you put aside ratios and educational level, the work environment itself is highly associated with differences in mortality across hospitals," she says.
By work environment, she means that nurses and physicians have good communication, trust, and teamwork; that management listens to nurses' concerns and acts to solve problems; that the organization has adequate staffing for all types of jobs; that employers invest in nurses' continuing education; and that the organization involves nurses in its major decisions.