Research links ratios to better outcomes

A massive and growing body of research in a wide variety of international settings is demonstrating a strong link between higher levels of nurse staffing and lower hospital-related mortality, lower incidences of failure to rescue, and better and safer patient outcomes. The Lamp looks at some of these studies.

The evidence is mounting that inadequate nurse staffing levels lead to an increase in negative outcomes for patients and ultimately a greater burden of cost to the health system and society.

One of the most compelling analyses comes from an American review by RL Kane and colleagues of 94 separate studies conducted between 1990 and 2006. This extensive pooled data threw up some powerful conclusions.

The review assessed the effect of increasing RN skill mix and concluded that “every additional RN FTE Per Patient Day was associated with a relative risk reduction in hospital-related mortality by 9% in ICUs and 16% in surgical patients.”

Kane estimated that an increase by one full-time RN per patient day would save five lives per 1000 medical patients, and six per 1000 surgical patients.

Every additional patient per RN per shift was associated with a 7% increase in relative risk of hospital-acquired pneumonia, a 53% increase in pulmonary failure, a 45% increase in unplanned extubation, and a 17% increase in medical complications.

According to the study, “one additional patient per RN per shift would result in 12 additional cases of failure to rescue, six cases of pulmonary failure and five accidental extubations per 1000 hospitalised patients”.

The study also found death rates decreased by 1.98% for every additional nurse hour.

Similar results in Europe

There has been consistency in results found across different continents. A survey of 1400 RNs in Finland and the Netherlands by Hinno, found that the incidence of patients falls increases when the patient to RN ratio is five and above.

“Most of noted adverse outcomes for patients occurred when RNs were responsible for five or more patients. This applies to incidence of patients falling down, falling off a chair, out of bed etc and leaving the unit without permission” the study found.

In the Netherlands, the occurrence of hospital infection progressively increased with increases in the patient-to-nurse ratio.

A massive cross-continental survey of nurses in the United States and Europe by Aitken and colleagues, backs up these analyses.

Aitken’s surveyed US nurses in 488 general acute hospitals, and European nurses in 12 countries and 617 hospitals. The study also looked at patient satisfaction data.

“Our results suggest that the associations between nursing and the quality and safety of hospital care are remarkably similar across Europe and in the US. Thus, efforts to improve hospital work environments and quality of care in any of these countries could be effective elsewhere,” the report says.

The study found that “each additional patient per nurse increased the odds of nurses reporting poor or fair quality care, and poor or failing safety grades.

“Patients in hospitals with higher ratios of patients to nurses … were less likely to rate their hospital highly and to recommend their hospital.”

Another US team led by Bobay (2012), looked at 16 medical/surgical units in four magnet hospitals to study the effect of staffing levels on post-discharge presentation to ED within 30 days. It estimated the likelihood of a patient representing or being readmitted.

Bobay found that the odds of an unplanned related ED visit following discharge decreased by 45% for every increase of 0.71 RN hours per patient day.

Research vindicates our ratios campaign

NSWNMA General Secretary Brett Holmes says the amount of empirical evidence that shows the value of ratios to patient care is now formidable.

“There are now a large number of significant studies – from the United States and Europe as well as from Australia – that describe the significant link between nurse-to-patient ratios/nursing hours per-patient-day and patient outcomes.

“There is growing evidence that clearly demonstrates that inadequate nurse staffing levels lead to an increase in negative outcomes for patients. It also leads to a greater burden of cost to both the healthcare budget and society.

“These results are not that surprising. A nurse is the only member of a healthcare team that is a continuous presence at the bedside. So the nurse is the most likely person to pick up a deterioration in a patient’s condition and initiate a response that minimises adverse events and negative outcomes for the patient.

“The research vindicates our campaign to have ratios implemented in New South Wales and increases our determination to see ratios strengthened and extended.”

Community nurses needed for research

The NSWNMA is to undertake research into community health nursing as part of the 2013 Public Health System Award campaign. The participation of community nurses in this research project is vital. The research will:

  • Determine the factors that may impact on the quality of patient care (e.g., workload or lack of resources) in NSW community nursing organisations; and
  • Identify the organisational attributes that community nurses consider important for professional practice.

We will be sending a link to an online questionnaire to all our community health nurse members later this month. The questionnaire will take about 15 minutes to complete and neither you nor your organisation will be identifiable.

For more information contact Dr Thomas Harding at