NEW YORK (Reuters) - Both the quality and quantity of nurses on a hospital staff have significant influence on the chances patients will die following even simple surgery, according to a large new study.
Researchers found the proportion of staff nurses with a bachelor's degree and the number of patients each nurse had to care for could add up to a difference of 30 percent or more in mortality rates for inpatients.
"If you go to a hospital in a developed country like the U.S. or UK, you think you'd get equal care, but that's really not the case," said the study's lead author, Linda Aiken, a professor of nursing and director of the Center for Health Outcomes and Policy Research at the University of Pennsylvania in Philadelphia.
"Research suggests we haven't really made any progress in decreasing deaths even though we've been spending lots of money on patient safety. We wanted to look at a potential solution, and we think that's nursing," she told Reuters Health.
Aiken and her team found that for every 10 percent increase in the number of staff nurses with a bachelors degree, there was a 7 percent lower risk of patient death within a month of being admitted to the hospital.
On the other hand, boosting a nurse's workload by one patient increased the likelihood of an inpatient dying within 30 days of admission by 7 percent.
"These associations imply that patients in hospitals in which 60 percent of nurses had bachelor's degrees and nurses cared for an average of six patients would have almost 30 percent lower mortality than patients in hospitals in which only 30 percent of nurses had bachelor's degrees and nurses cared for an average of eight patients," Aiken and her colleagues write in The Lancet.
Their study used medical data on more than 422,000 patients over the age of 50 that had been collected between 2007 and 2009 as part of RN4CAST, an effort funded by the European Commission to gather information about the nursing workforce from 488 hospitals in 12 European countries.
Aiken's team focused on 300 hospitals in nine European countries, including Ireland, Norway, Spain and Switzerland. The patients there had undergone common surgeries, such as an appendectomy, knee replacement surgery or gallbladder removal, which are not linked to a high risk of death but still require a stay in the hospital afterwards.
The research team also took into account the patients' preexisting health problems, including HIV or AIDS, kidney disease and cancer.
Surveys of more than 26,000 nurses working in the hospitals included in the study were also part of RN4CAST, and measured the professional nurses' education levels, along with the usual number of patients each nurse was expected to take care of during his or her shift.
"This study was the first to examine nursing workforce data across multiple nations in Europe and was unique in that it assessed actual clinical outcomes, rather than patient- or nurse-reported outcomes," Patricia Grady, director of the National Institute of Nursing Research, wrote in an email to Reuters Health.
The Institute is part of the U.S. National Institutes of Health and was one of the funding sources for the study.
Worldwide, there are multiple routes to becoming a nurse; for example, some include first obtaining a bachelors degree, whereas others require much less schooling - the equivalent of completing only part of high school - followed by a nursing degree.
The difference in patient deaths between nurses with and without a bachelors degree likely stems from the nurses' abilities to think critically and discuss patient care freely with other hospital staff, such as physicians, Aiken said.
"Nurses with a college degree are more likely to command respect, to act confidently and to be able to negotiate," Aiken said.
The results are particularly relevant as hospitals and policymakers look to decrease costs - sometimes by cutting nursing staff.
"Nursing is the largest workforce in a hospital, and is therefore the most expensive," said Pat Stone, director of the Columbia University School of Nursing's Center for Health Policy in New York.
"Some administrators and policy makers see a need to cut labor expenses and therefore cut staffing or hire less expensive nurses," said Stone, who was not involved in the new study.
Yet such decisions may be short-sighted and threaten patient safety down the road.
"These results should be used to advocate for an educated nurse workforce with reasonable workloads so they may best care for their patients. In the long run, the healthcare system is likely to save money," Stone said.
SOURCE: bit.ly/1k7O3nR The Lancet, online February 26, 2014.