WASHINGTON (April 2, 2025) — A new study suggests that when hospitals rely excessively on nurses who are either travel nurses or working overtime, a key patient safety indicator may suffer.
Research has demonstrated that nurse staffing is an important determinant of quality provided by hospitals. At the same time, few studies have looked at the differential effects of using nursing agencies, and/or requesting, and in some cases, mandating, overtime hours for regular nurse staff.
The new study by researchers at the George Washington University and Premier, Inc. is one of the first to look at how the increased use of agency nurses and of overtime hours can affect patient safety.
“Our study shows that when hospitals over rely on travel nurses or overtime for the regular nursing staff, patient safety care may be compromised,” said Patricia (Polly) Pittman, lead author of the study and Director of the Fitzhugh Mullan Institute for Health Workforce Equity at the GW Milken Institute School of Public Health. “Hospitals that want to improve safety should closely track their reliance on overtime and especially nurse staffing agencies.”
The researchers looked at data from 70 US hospitals from January 2019 through December 2022. The team also looked at several measures of quality including rates of pressure ulcers.
Pressure ulcers develop when pressure cuts off blood flow to the skin. They are markers of poor care in health care facilities because adequate levels of nursing care can prevent these potentially dangerous wounds from developing in the first place.
The team found that beyond a certain point, reliance on nurse overtime and agency nurse hours were associated with increased rates of pressure ulcers.
The study notes that hospitals need to schedule overtime and use agency nurses in some cases to fill in for a nursing shortage. But too much reliance on such solutions, especially the heavy use of travel nurses, can potentially harm patients.
The team also found that more than half of the hospitals in the study used more nurse overtime and agency hours than was safe, resulting in higher rates of pressure ulcers than those facilities that remain below the breakpoint.
This study adds to the growing body of data that highlights the importance of using contingent labor judiciously,” said John Martin, Vice President Data Science for Premier. “We have seen similar findings in the Workforce Innovation Collaborative at Premier, which shows that use of contingent labor among CMS 4- and 5-Star Hospitals in our workforce database more rapidly declined in 2023 and 2024 when compared to the rest of the country.”
The study concludes that overtime and agency nurse hours may be useful for short periods, but should not be considered an alternative to maintaining adequate regular nurse staffing. Hospitals that want to improve patient safety measures such as pressure ulcers should consider tracking their use of overtime and agency nurse hours in relation to patient outcomes.
The study, Increased Utilization of Overtime and Agency Nurses and Patient Safety, was published in JAMA Network Open April 2.