Supplemental nurses could be “lifesavers” during times of critical nurse shortages in U.S. hospitals, according to a new study by University of Pennsylvania School of Nursing researchers. The study, “Hospital Use of Agency-Employed Supplemental Nurses and Patient Mortality and Failure to Rescue,” was published in Health Services Research.

“Our study showed these nurses could be lifesavers. Hiring temporary nurses can alleviate shortages that could produce higher patient mortality,” said Linda Aiken, lead researcher of the study and a professor of sociology and nursing and director of the University of Pennsylvania Center for Health Outcomes and Policy Research.

The study also concludes that poor patient outcomes once believed associated with the hiring of supplemental nurses in hospitals are likely caused by poor working conditions within those hospitals.

The study was based on data collected in California, Florida, New Jersey and Pennsylvania. It examined controlled data from more than 1.3 million patients and 40,000 nurses in more than 600 U.S. hospitals.