Nurse-to-patient ratios and their impact on patient safety and mortality

Nurse-to-Patient Ratios: Is it Important?

The climate and role of the acute care nurse has drastically changed over the last three decades. The rising costs of healthcare and diminishing coverage and reimbursements from health insurance carriers have prompted acute care facilities to cut costs and modify procedures to remain profitable and competitive. The largest expense of any for-profit organization is payroll. Unfortunately, staff reductions are typically included in cost cutting efforts by management. Nursing staff levels are often impacted the most in hospitals trying to decrease costs. Hospitals have reduced inpatient admissions to the most critical patients. Shorter lengths of stay and fewer complications after surgeries are attributable to improvements in surgical procedures and technology. These factors lead to higher concentrations of patients requiring acute care.

Introduction:

Nurse-to-patient ratios refers to the number of patients each nurse has to care for. A history of nurse staffing and patient outcomes dates as far back as a study by Moses and Mosteller (1968).

They found nurse staffing among the significant determinants of mortality (as cited in Aiken, 2005). Later, publicly available Medicare data for U.S. hospitals generated more studies on the factors related to mortality. (Shortell & Hughes, 1988; Hartz, Krakauer, & Kuhn 1989; Silber, Kennedy, & Even-Shoshan, 2000). Authors of these studies reported that nurse staffing was significantly related to mortality (as cited in Aiken, 2005). Aiken, Clarke, Sloane, Sochalski, and Silber (2002b) produced the first study to specifically quantify the impact of nurse-to-patient ratios on death rates.

Minimum staffing ratios represent the minimal amount of nurses required to care for the maximum number of patients, without compromising patient or nurse safety. Both the public and physicians rank nurse understaffing of hospitals as one of the most serious threats to patient safety (Blendon, DesRoches & Brodie, 2002). Patient safety experts are concerned whether or not inappropriate ratios lead to higher mortality rates and a variety of complications and adverse effects as well as higher patient stays at hospitals. Nurse safety advocates are beginning to question if there is an appropriate number of each type of staff member within a healthcare facility, and, if there isn't how does it impact job satisfaction and the ability of nursing staff to have adequate multidisciplinary interaction to improve quality of care.

One suggested solution to ensure safe and effective nurse staffing has been to mandate nurse staffing ratios. Currently, California has minimum nurse-to-patient ratios resulting from the passage of AB 394 in the states legislator which went into effect in 2004 (Spetz, 2004). However, California is the only state to do so, calling to question whether other states or the federal government ought to follow suit.

Quality of Care / Patient Safety

More than one-third of practicing physicians and 40% of the public say either they or a family member have experienced a medical error and 53% of the physicians and 65% of the public believe nurse understaffing is a factor in these errors (Kaiser Family Foundation/Agency for Healthcare Research and Quality/Harvard School of Public Health, 2004). Results of a Harris Poll revealed that more than half ofAmericans believe the quality of health care that people receive is affected "a great deal" by a shortage of nurses (Harris Poll, 1999).

Aiken, Clarke, Sloane, Sochalski, and Silber (2002b) estimated that 20,000 people die each year because they have checked into a hospital with overworked nurses. They reported that patients scheduled for routine surgeries run a 31% greater risk of dying if they are admitted to a hospital with a severe shortage of nurses. The risk of death increased by 7% for each additional patient cared for over four patients at a time.

According to Beth Piknick, president of the Massachusetts Nurses Association, "Make no mistake about it, every day in Massachusetts patients are suffering in pain; patients are being neglected; patients are falling; patients are experiencing preventable and costly complications simply because their nurse is not there when they need them to be there because he or she is struggling to meet the needs of too many other patients." (as cited in MNA, 2006)

Context

Architecture (geographic dispersion of patients, size and layout of individual patient rooms, arrangement of entire patient care unit(s), and so forth); technology (beepers, cellular phones, computers); same unit or cluster of patients

Expertise

Learning curve for individuals and groups of nurses; staff consistency, continuity and cohesion; cross-training; control of practice; involvement in quality improvement activities; professional expectations; preparation and experience

Source: American Nurses Association (2005), 2005 Principles for Nurse Staffing, Retrieved December 6, 2006 at http://www.nursingworld.org/readroom/stffprnc.htm

Nurse Safety / Job Dissatisfaction

While nurse safety is a big concern, its goal is mostly to decrease the workload so the nurse can effectively care for patients. Aiken, Clarke, Sloane, Sochalski, and Silber (2002) reported that each additional patient assigned to a nurse was associated with a 23% increase in the odds of job burnout and a 15% increase in the possibility of job dissatisfaction. They also reported that 40% of hospital nurses experience burnout levels that surpass the average for health care workers and that higher nurse-to-patient ratios are directly attributed to elevated emotional exhaustion and job dissatisfaction among nurses. Their research results further indicate that nurses working in hospitals with higher ratios are more than twice more likely to experience job burnout and dissatisfaction than nurses at hospitals with the lowest ratios. Likewise, Sheward, Hunt, Hagen, Macleod and Ball (2005) found that high patient to nurse ratios were associated with increased risk of emotional exhaustion and dissatisfaction with current job. Nurses who continuously work overtime or work without adequate backup incur greater absenteeism and poorer health.

Consensus / Professionalism

High patient to nurse ratios impede collaboration that has been proven to have an important positive impact on patient outcomes. Knaus, Draper, Wagner, & Zimmerman (1986) found that in hospitals where both the nurses and physicians agreed that their communication and collaboration were positive, deaths were 41% lower than ICU predictive tools had forecast. Conversely, they also discovered that in hospitals where nurses and physicians reported that there was little communication and collaboration, 58% of patients died even though the predictive tool had forecast that they would live.

Malila & Von Reuden (2002) have also found that a collaborative approach to care between nurses and physicians has a positive impact on quality of care. Kaye, Erickson, Zeiler, Gavigan and Gannon (2000) have found this type of multidisciplinary interaction reduces ventilator-associated pneumonia rates and decreases readmissions to an intensive care unit.

Patient Outcomes: Studies Supporting the Influence of Nurse-to-Patient Ratios

Aiken and colleagues have been pioneers in studying nurse patient ratios and their relationship to patient outcomes.

Aiken, Sochalski, and Lake (1997) demonstrated that nursing presence, whether measured as RN ratios or as RN hours relative to other nursing personnel hours, is significantly correlated to mortality. When studying patient outcomes in specialized AIDS units,

Aiken, Sloan, Lake, Sochalski, and Weber (1999) found that at 30 days post admission, mortality rates were 60% lower in magnet hospitals, and 40% lower in dedicated AIDS units than in conventional scattered bed units. The researchers concluded that higher nurse patient ratios were a major factor in these lower