Campus & Community

SPH study: More nurses equals better patient health

2 min read

The size and mix of nurse staffing in U.S. hospitals has a direct impact on the outcome of patient health. The finding comes from the most comprehensive study to date on the topic and was led by Jack Needleman of the Harvard School of Public Health and Peter Buerhaus of Vanderbilt University’s School of Nursing in Nashville, Tenn. The study, “Nurse Staffing Levels and Patient Outcomes in Hospitals” is available at

Hospital discharge data for more than 5 million patients, financial reports, and hospital staffing surveys from 799 hospitals in 11 states were analyzed to determine staffing levels of registered nurses (RNs), licensed practicing/vocational nurses (LPNs/LVNs), and aides, and to measure the frequency of a wide range of complications that patients developed during their hospital stay.

The researchers found consistent relationships between nurse staffing variables and five adverse patient outcomes: urinary tract infections, pneumonia, shock, upper gastrointestinal bleeding, and length of hospital stay in medical and major surgery patients. They also found higher RN staffing was associated with a 3-12 percent reduction in certain adverse outcomes, and higher staffing at all levels of nursing was associated with a 2-25 percent reduction in adverse outcomes

Mortality and complication rates analyzed in the study were higher in medical patient samples than in the surgical patient samples, 3.15 percent compared with 1.6 percent. The rate of death from one of the five severe complications was 18.6 percent for medical patients and 19.7 percent for major-surgery patients.

“Patient outcomes like hospital-acquired pneumonia, shock and cardiac arrest, and gastrointestinal bleeding have a substantial risk of death associated with them – and hospital-acquired urinary tract infections are far too common,” said Needleman, assistant professor of economics and health policy at the School of Public Health and project director for the study, “The goal should be to reduce them to zero, if possible. Our study underscores that nurse staffing is an important element in improving patient safety.”

“The study findings show that nurse staffing matters considerably to the well-being of hospital patients,” said Buerhaus, co-project director for the study and senior associate dean for research at Vanderbilt University’s School of Nursing. “Perhaps the study results will move health policy forward, making it possible to provide hospitals and nurses with the resources that will enrich staffing levels to the point where the adverse patient outcomes we found can be reduced.”