A major new study for the New England Journal of Medicine found that the risk of hospital patient mortality increases proportionally with nurse staffing shortages at a given time.
Patients mortality risk rises not only with the number of below-target nursing shifts to which they are exposed, but also with an increase in nurses workloads during shifts because of high patient turnover, according to researchers with the UCLA School of Public Health, Mayo Clinic and Vanderbilt University.
Jack Needleman, professor of health services at UCLAs School of Public Health, and colleagues analyzed the records of nearly 198,000 admitted patients and 177,000 eight-hour nursing shifts across 43 patient-care units at a large tertiary academic medical center in the U.S.
For each shift patients were exposed to that was substantially understaffed, meaning eight or more hours below the target level based on patient volume and needs, overall mortality risk rose by 2%. Because the average patient in the study was exposed to three nursing shifts that fell below target levels, the mortality risk for these patients was 6% higher than for patients on units that were always fully staffed.
Additionally, for each shift a patient experienced in which turnover because of admissions, discharges and transfers was substantially higher than usual, the risk of mortality was 4% higher. The average patient in the study was exposed to one high-turnover shift.
The researchers said their study improves on previous analyses, which drew many of the same conclusions. Critics challenged those studies, saying the data used did not allow researchers to link staffing directly to the precise hospital units on which patients stayed or to the nursing shifts to which they were exposed.
The earlier studies also did not include information on how staffing decisions were made, nor did they allow researchers to control all variations across hospitals that might contribute to differences in mortality.
By examining a single hospital rather than comparing hospitals, the researchers are confident they addressed those criticisms.
Since the hospital we studied delivers high-quality care, has low mortality rates, has high nurse-staffing targets and meets its targets over 85% of the time, its unlikely the increased mortality we observe is due to general quality problems, Needleman said.
We believe that these findings apply to all hospitals those like the one we studied, where staffing is generally high and targets are usually met, and hospitals that are less successful in achieving staffing levels needed to meet patient needs and keep them safe.
The American Nurses Association said the study reinforces ANA principles that call for nurse staffing to be flexible and continually adjusted based on patients needs and other factors.
This study demonstrates that hospitals must implement staffing systems that are flexible enough to meet the individual needs of each patient for every shift, every unit and every day, said ANA President Karen A. Daley, RN, PhD, MPH, FAAN. It shows that nurse staffing should not be viewed as a cost to be minimized, but as a critical factor in producing quality patient outcomes ultimately saving lives.
In a news release, ANA lauded the recommendation by the studys authors that health policy experts should shift the focus from examining whether nurse staffing levels affect patient outcomes to determining how the healthcare payment system can provide incentives that reward hospitals efforts to ensure adequate staffing and improve the quality of care.