RATIOS: Scientific Research Linking Safe Nurse Staffing to Patient Safety
Medical Care: January 2013
Improving nurses’ work environments and staffing may be effective interventions for preventing readmissions. Each additional patient per nurse was associated with the risk of within 30 days of readmission for heart failure (7%), myocardial infarction (9%), and pneumonia (6%). “In all scenarios, the probability of patient readmission was reduced when nurse workloads were lower and nurse work environments were better.”
State-Mandated Nurse Staffing Levels Lead to Lower Patient Mortality and Higher Nurse Satisfaction
Agency for Healthcare Research and Quality, September 26, 2012
The California safe staffing law has increased nurse staffing levels and created more reasonable workloads for nurses in California hospitals, leading to fewer patient deaths and higher levels of job satisfaction than in other states without mandated staffing ratios. Despite initial concerns from opponents, the skill mix of nurses used by California hospitals has not declined since implementation of the mandated ratios.
Nurse Staffing, Burnout, and Health-Care Associated Infection
American Journal of Infection Control, August 2012
For each additional patient assigned to a nurse, there was roughly one additional infection per 1,000 patients, costing hospitals millions of dollars and endangering patients.
Healthcare associated infections are associated with morbidity, mortality, and enormous costs to health care facilities, and insurance providers nationwide are denying payment for costs associated with these infections. Healthcare facilities can improve nurse staffing and other elements of the care environment and alleviate job-related burnout in nurses at a much lower cost than those associated with healthcare-associated infections. “It is costing hospitals more money not to spend money on nursing,” said Linda Aiken, the lead author.
Nurse Staffing and Inpatient Hospital Mortality
New England Journal of Medicine, March 17, 2011
"Studies involving RN staffing have shown that when the nursing workload is high, nurses' surveillance of patients is impaired, and the risk of adverse events increases."
"… We found that the risk of death increased with increasing exposure to shifts in which RN hours were 8 hours or more below target staffing levels or there was high turnover. We estimate that the risk of death increased by 2% for each below-target shift and 4% for each high-turnover shift to which a patient was exposed."
Implications of the California Nurse Staffing Mandate for Other States
Health Services Research, August 2010
The researchers surveyed 22,336 RNs in California and two comparable states, Pennsylvania and New Jersey, with striking results, including: if they matched California state-mandated ratios in medical and surgical units, New Jersey hospitals would have 13.9 percent fewer patient deaths and Pennsylvania 10.6 percent fewer deaths.
“Because all hospitalized patients are likely to benefit from improved nurse staffing, not just general surgery patients, the potential number of lives that could be saved by improving nurse staffing in hospitals nationally is likely to be many thousands a year,” according to Linda Aiken, the study’s lead author.
California RNs report having significantly more time to spend with patients, and their hospitals are far more likely to have enough RNs on staff to provide quality patient care. Fewer California RNs say their workload caused them to miss changes in patient conditions than New Jersey or Pennsylvania RNs
The Economic Value of Professional Nursing
Medical Care, January 2009
The findings in this report demonstrate that as nurse staffing levels increase, the risk of complications and the length of hospital stays decrease, leading to savings in medical costs, improved national productivity, and saved lives.
Adding 133,000 RNs to the acute care hospital workforce across the U.S. would produce medical savings estimated at $6.1 billion in reduced patient care costs, not including the value of increased productivity when nurses help patients recover more quickly, an estimated additional $231 million per year. Combining medical savings with increased productivity, the partial estimates of economic value averages $57,700 for each of the additional 133,000 RNs.
The Impact of Medical Errors on 90-Day Costs and Outcomes: An Examination of Surgical Patients
Health Services Research, July 2008
This found that the large difference in calculations for medical error expenses might mean that interventions to increase patient safety -- like adding more nursing staff -- could be more cost-effective than previously reported.
The study found that insurers paid an additional $28,218 (52 percent more) and an additional $19,480 (48 percent more) for surgery patients who experienced acute respiratory failure or post-operative infections, respectively, compared with patients who did not experience either error.
Preventing these and other preventable medical errors would reduce loss of life and could reduce healthcare costs by as much as 30 percent, the researchers said.
"The point of our paper is that the cost savings from reducing medical errors are much larger than previously thought." Pointing to previous research that looked at the business case for improving RN staffing ratios, the researchers concluded: "It is quite possible that the post-discharge costs savings achieved by reducing adverse events might just be enough for the hospital to break-even on the investment in nursing."
Overcrowding and Understaffing in Modern Health-care Systems: Key Determinants in Meticillin-resistant Staphylococcus Aureus Transmission
Lancet Infectious Disease, July 2008
This study finds that understaffing of nurses is a key factor in the spread of methicillin-resistant Staphylococcus aureus (MRSA), the most dangerous type of hospital-acquired infection. The authors note that common attempts to prevent or contain MRSA and other types of infections such as requirements for regular and repeated hand washing by nurses are compromised when nursing staff are overburdened with too many patients.
Survival From In-Hospital Cardiac Arrest During Nights and Weekends
JAMA, February 20, 2008
A national study on the rate of death from cardiac arrest in hospitals found that the risk of death from cardiac arrest in the hospital is nearly 20 percent higher on the night shift. The authors highlight understaffing during the night shift as a potential explanation for the death rate. “Most hospitals decrease their inpatient unit nurse-patient ratios at night… Lower nurse-patient ratios have been associated with an increased risk of shock and cardiac arrest,” the authors stated.
Nurse Staffing and Patient, Nurse and Financial Outcomes
American Journal of Nursing, January 2008
This report provides a comprehensive literature review of more than 21 studies published since 2002 that, according to the author, “underscore the importance of hospitals acknowledging the effect nurse staffing has on patient safety, staff satisfaction, and institutions’ financial performance.” According to the report, “the evidence clearly shows that adequate staffing and balanced workloads are central to achieving good patient, nurse, and financial outcomes. Efforts to improve care, recruit and retain nurses, and enhance financial performance must address nurse staffing and workload. Indeed, nurses’ workloads should be a prime consideration.”
The Impact of Nurse Staffing on Hospital Costs and Patient Length of Stay: A Systematic Review
Nursing Economics, Vol. 25, 2007
This study provides a comprehensive review of the research on the impact of RN staffing ratios on hospital costs and patient length of stay (LOS). It identified 17 studies published between 1990 and 2006 and concluded: "the evidence reflected that significant reductions in cost and LOS may be possible with higher ratios of nursing personnel in hospital settings. Sufficient numbers of RNs may prevent patient adverse events that cause patients to stay longer than necessary. Patient costs were also reduced with greater RN staffing as RNs have higher knowledge and skill levels to provide more effective nursing care as well as reduce patient resource consumption. Hospital administrators are encouraged to use higher ratios of RNs to non-licensed personnel to achieve their objectives of quality patient outcomes and cost containment."
Staffing Level: a Determinant of Late-Onset Ventilator-Associated Pneumonia
Critical Care, July 19, 2007
Understaffing of registered nurses in hospital intensive care units increases the risk of serious infections for patients; specifically late-onset ventilator-associated pneumonia, a preventable and potential deadly complication that can add thousands of dollars to the cost of care for hospital patients. Curtailing nurse staffing levels can lead to suboptimal care, which can raise costs far above the expense of employing more nurses
Nurse Working Conditions and Patient Safety Outcomes
Medical Care,Journal of the American Public Health Association, June 2007
A review of outcomes for more than 15,000 patients in 51 U.S. hospital ICUs showed that those with higher nurse staffing levels had a lower incidence of infections, such as central line associated bloodstream infections, a common cause of death in intensive care settings.
The study found that patients cared for in hospitals with higher staffing levels were 68 percent less likely to acquire an infection. Other measures such as ventilator-associated pneumonia and skin ulcers were also reduced in units with high staffing levels.
Patients were also less likely to die within 30 days in these higher-staffed units. Increasing RN staffing could reduce costs and improve patient care by reducing unnecessary deaths and reducing days in the hospital.
Hospital Nurse Staffing and Quality of Patient Care
Evidence Report/Technology Assessment for Agency for Healthcare Research and Quality, May 2007
A comprehensive analysis of all the scientific evidence linking RN staffing to patient care outcomes found consistent evidence that an increase in RN-to-patient ratios was associated with a reduction in hospital-related mortality, failure to rescue, and other nurse sensitive outcomes, as well as reduced length of stay.
Quality of Care for the Treatment of Acute Medical Conditions in U.S. Hospitals
Archives of Internal Medicine, Dec 2006
A national study of the quality of care for patients hospitalized for heart attacks, congestive heart failure and pneumonia found that patients are more likely to receive high quality care in hospitals with higher registered nurse staffing ratios.
Longitudinal Analysis of Nurse Staffing and Patient Outcomes - More About Failure to Rescue
Journal of Nursing Administration, Jan. 2006
Increasing RN staffing increased patient satisfaction with pain management and physical care; while having more non-RN care "is related to decreased ability to rescue patients from medication errors."
Nurse Staffing in Hospitals: Is There a Business Case For Quality?
Health Affairs, Jan.-Feb. 2006
Researchers estimated that more than 6,700 in-hospital patient deaths and overall 70,000 adverse outcomes could be avoided by increasing nurse staffing.
Correlation Between Annual Volume of Cystectomy, Professional Staffing, and Outcomes - A Statewide, Population-Based Study
Cancer, Sept. 2005
Patients undergoing common types of cancer surgery are safer in hospitals with higher RN-to-patient ratios. High RN-to-patient ratios were found to reduce the mortality rate by greater than 50% and smaller community hospitals that implement high RN ratios can provide a level of safety and quality of care for cancer patients on a par with much larger urban medical centers that specialize in performing similar types of surgery.
Improving Nurse-to-Patient Staffing Ratios as a Cost-Effective Safety Intervention
Medical Care, Aug. 2005
Cutting nurse to patient ratios to 1:4 nationally could save as many as 72,000 lives annually. “Considered as a patient safety intervention, improved nurse staffing has a cost-effectiveness that falls comfortably within the range of other widely accepted interventions.”
Is More Better? The Relationship Between Nurse Staffing and the Quality of Nursing Care in Hospital
Medical Care, February 2004
Survey of 8,000 RNs in Pennsylvania hospitals found workload and understaffing contributed to medical errors, patient falls and a number of important nursing tasks left undone at the end of every shift.
Keeping Patients Safe: Transforming the Work Environment of Nurses (Executive Summary)
Institute of Medicine, National Academy of Sciences, November 2003
The Institute for Medicine calls for improved nurse-to-patient ratios, limits on mandatory overtime, and nurse involvement on every level to protect patients.
Nurse Staffing, Quality, and Hospital Financial Performance
Journal of Health, Summer 2003
Increased staffing of registered nurses does not significantly decrease a hospital's profit margin, even though it boosts the hospital's operating costs.???
The Effects of Nurse Staffing on Adverse Events, Morbidity, Mortality, and Medical Costs
Nursing Research, March/April 2003
Increasing nurse staffing by just one hour per patient day resulted in a 9% reduction in the incidence of hospital-acquired pneumonia. The cost of treating hospital-acquired pneumonia was up to $28,000 per patient. Patients who had pneumonia, wound infection or sepsis had a greater probability of death during hospitalization.
Hospital Nurse Staffing and Patient Mortality, Nurse Burnout, and Job Dissatisfaction
Journal of the American Medical Association, Oct. 22, 2002
For each additional patient beyond four assigned to an RN, the risk of death increases by 7% for all patients. “The effects imply that, all else being equal, substantial decreases in mortality rates could result from increasing registered nurse staffing.”
Strengthening Hospital Nursing
Health Affairs, Sept./Oct. 2002
"The implications of doing nothing to improve nurse staffing levels in many low-staffed hospitals are that a large number of patients will suffer avoidable adverse outcomes and hospitals and patients will continue to incur higher costs than are necessary."
Nurse Staffing and Healthcare-associated Infections
Journal of Nursing Administration, June 2002
"There is compelling evidence of a relationship between nurse staffing and adverse patient outcomes," including serious bloodstream infections in hospital patients.
Nurse Staffing Levels and Quality of Care in Hospitals
New England Journal of Medicine, May 30, 2002
Poor hospital registered nurse staffing is associated with higher rates of urinary tract infections, post-operative infections, pneumonia, pressure ulcers and increased lengths of stay, while better nurse staffing is linked to improved patient outcomes.
Health Care at the Crossroads: Strategies for Addressing the Evolving Nursing Crisis
Joint Commission on Accreditation of Healthcare Organizations (JCAHO), 2002
JCAHO found that low staffing levels were a contributing factor in 24% of patient safety errors resulting in injuries or death since 1996.
Intensive Care Unit Nurse Staffing and the Risk of Complications After Abdominal Aortic Surgery
Effective Clinical Practice, Sept./Oct. 2001
Patients treated in hospitals with fewer ICU nurses were more likely to have medical complications, respiratory failure or need a breathing tube inserted.
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