Introduction

Nurses are essential to patient care, and having an appropriate nurse staffing level is critical to patient safety. Nurses are responsible for many tasks related to direct patient care in health care, and research suggests that nurse staffing is highly correlated with patient outcomes. Specifically, having fewer nurses caring for patients is associated with higher patient mortality. In a study controlling for institutional differences across three sites in an academic medical center, patient mortality was higher with low nurse staffing but not correlated to other factors like patient turnover. Additional studies have come to similar conclusions.¹

The high demand for qualified nurses has outpaced supply, causing nursing shortages, which were further exacerbated by the COVID-19 pandemic.² The nursing workforce has increased steadily since the 1970s. In 1982, there were about one million registered nurses (RNs) in the United States; by 2020, that number had grown to 3.2 million.³ Although this shows nursing is a growing profession, it has not been able to keep up with the demand for nursing staff. Data from 2020 to the present show that younger nurses are leaving the profession at higher rates than previously observed, and there has been a decrease in interest among students in pursuing nursing as a career.³ In 2022, there were more job openings for RNs than for any other profession in the United States.⁴ The demand for nurses is increasing as the needs of an aging U.S. population also increase and staffing for other healthcare professionals, like physicians, remains low.³ Moreover, about one-third of the total number of nurses in the nursing workforce is above the age of 50 and likely to retire in the next 15 years.⁴

Nursing Workforce Challenges and Patient Safety

Inadequate nurse staffing can lead to missed nursing care and negative patient outcomes, such as patient mortality. Missed nursing care refers to necessary nursing care that is not completed, often because nurses do not have enough time to provide such care due to low nurse staffing levels. Many patient outcomes and safety outcomes appear to be connected to nursing levels, including length of hospital stay, patient dissatisfaction with care, and hospital readmissions. Although the correlation between patient outcomes, patient safety, and nurse staffing levels is complex, appropriate levels of nurse staffing tend to reduce avoidable patient harm.⁵ Appropriate staffing is not a static number; rather, it takes into account the relative mix of nurses providing care and their workload, expertise, and available resources.⁶

After controlling for patient and hospital characteristics, studies have shown that missed nursing care is correlated with an increased risk of death.⁷ In addition, missed care is consistently shown to be more prevalent with low nurse staffing in the United States and in international contexts.⁷ Research shows that the use of support workers, such as nursing assistants, did not reduce and in some cases worsened missed nursing care, possibly due to nurses having to supervise or double-check the work of support staff.⁷ This research suggests that achieving appropriate levels of nurse staffing is critical for patient safety.

Addressing Workforce Challenges

Nurses are essential to patient care and patient safety, as they are the healthcare professionals with the most patient contact and coordinate care among other healthcare professionals. In recognition of this essential role, some states have instituted minimum statutory levels of nurse staffing. Appropriate levels of nurse staffing vary by setting and even on a shift-by-shift basis depending on the availability of other staff and the mix of nursing skills.

To compensate for nurse shortages and to achieve appropriate nurse staffing, some healthcare systems have turned to temporary nurse staffing. Such staffing includes (1) non-unit-based nursing staff, (2) float nurses who are redeployed from one department in a hospital or health system to another unit on a temporary basis, (3) agency nurses who are hired from temporary staffing agencies that are usually local to the hospital, and (4) travel nurses who are hired from agencies and move from city to city on temporary nursing assignments. Healthcare systems have, at times, attempted to compensate for nurse shortages by using these forms of temporary nurse staffing.

Using agency nurses and nurses that float between departments is not new; such nurses typically represent a small percentage of the nursing workforce. Since the 1980s, agency nurses who are hired through local contracts have accounted for about 3.8% of the nursing workforce. In addition, travel nurses represent, on average, about 3–4% of hospitals’ overall nurse staffing.⁸ In August 2021, agency nurses accounted for 8–10% of hospital staffing.⁸ However, this high utilization of agency nurses may be decreasing, perhaps by as much as one-third.⁹ Although agency nurses are typically paid 3 to 4 times the salary of permanent nurses, they report the highest rates of job dissatisfaction, burnout, and poor work-life balance compared to other types of nurses.^8,10 Given the continued staffing challenges faced by healthcare organizations and the critical role that nurses play in patient care, the patient safety implications of the use of agency nurses warrant further consideration.

Based on evidence from a variety of studies spanning 20 years, the effect of agency and travel nurse utilization on patient safety outcomes has been mixed, with agency and travel nurses sometimes correlated with better, worse, or no difference in patient outcomes.⁸ One review suggests that no single clinical area is most vulnerable to differences in patient safety outcomes when agency and travel nurses are used. Rather, by analyzing data in published studies through Donabedian’s model for quality of care, which differentiates structural variables from technical processes, researchers observed that agency and travel nurses tended to improve patient outcomes when staffing levels were better. They also found that, while agency and travel nurses are similarly educated compared to permanent nurses, they often have less experience.⁸

These findings support observations on the effect of teamwork on patient safety—namely, that more effective teamwork and communication mitigate patient safety risks. Although differences have been reported on patient variables like hospital-acquired pressure ulcers, falls, and medication errors on the basis of nurse experience, as well as on agency and travel nurse utilization, no consistent, statistically significant findings show a relationship between these variables.⁸ Work environment, which is another process variable from Donabedian’s model, offers another clue on the patient safety effects of agency and travel nurses. A strong work environment characterized by adequate nurse support and good nurse-physician rapport shows patient safety benefits, regardless of whether agency or permanent nurses are used.⁸ However, care settings with high agency nurse use tend to have lower ratings for work environment.⁸ Electronic health records are another work environment factor that may mitigate patient safety risks. It is possible that standardizing parts of the electronic health record across systems could reduce access issues that may reduce patient safety.

Evidence suggests that the use of agency nurses in and of itself is not sufficient to cause higher rates of unsafe patient care. A range of variables, including the relative experience level of nursing staff, pre-existing staffing levels, and work environments, may work in concert to make the use of agency nurses more or less safe. It is possible to create an environment with the teamwork and infrastructure necessary to achieve patient safety even when utilizing a variety of nursing staff, as noted in a report from the American Association of Critical-Care Nurses (AACN) and American Nurses Association (ANA).⁶ Including nurses and nurse leaders in staffing decisions and governance, modernizing care delivery models so that they are efficient and not burdensome to nurses, and improving regulatory oversight to include appropriate nurse staffing are all actionable interventions that can improve patient safety, even during nurse staffing shortages.⁶

The Future of Nurse Staffing

Although the use of agency and travel nurses increased rapidly during the COVID-19 pandemic, that level is likely unsustainable, given the high labor costs associated with using agency nurses. However, if the use of agency nurses does not decline, research indicates that agency nurses can be deployed safely in hospital units. Despite their initial unfamiliarity in new hospital settings, agency nurses often ensure that high-quality care is provided by preparing for assignments and taking care to effectively introduce themselves as well as prioritizing patient care, according to qualitative research.¹¹ Agency nurses contribute to patient safety and high-quality care as members of a strong healthcare team. High-quality care from nurses is essential for achieving patient safety based on findings from multiple studies that have found higher patient mortality with low nurse staffing.

As the amount and intensity of care increases for an aging U.S. population, the care provided by nurses will likely remain essential to patient safety and quality of care. With nursing shortages projected to last until at least 2030, high turnover and high rates of burnout are likely to continue, along with high demand for nurses. But these issues can be mitigated. Recently, professional organizations such as the ANA have noted and advocated for certain essential needs to generate a sustainable nursing workforce.⁶ These imperatives include supporting the nursing workforce through initiatives that are built for their needs, such as providing safe workplaces, the chance for advancement, and a voice in hospital governance. Such efforts could reduce the pressures that lead to high nurse turnover.

Authors

Katie Boston-Leary, PhD, MBA, MHA, RN, NEA-BC
Director of Nursing Programs
American Nurses Association
Silver Spring, MD

Merton Lee, PharmD, PhD
Researcher
American Institutes for Research (AIR)
Columbia, MD

Sarah E. Mossburg, RN, PhD
Senior Researcher
American Institutes for Research (AIR)
Columbia, MD

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