Large study links setting nurse-to-patient ratios with better outcomes

The findings come from a large study in Australia and prompted calls for the “important lessons” from the research to be considered by those involved in drawing up healthcare workforce strategies.

“We hope that our data convinces people of the need for minimum nurse-to-patient ratios”

Matthew McHugh

The study, involving 55 hospitals in Queensland, suggests that a recent state policy to introduce a minimum ratio of one nurse to four patients for day shifts has successfully improved patient care.

Researchers found a 7% drop in the chance of death and readmission, and a 3% reduction in length of stay for every one less patient a nurse had on their workload.

The study, published in The Lancet, involved more than 400,000 patients and 17,000 nurses in 27 hospitals that implemented the policy and 28 hospitals that did not for comparison.

It is the first prospective evaluation of the health policy aimed at boosting nurse numbers in hospitals to ensure a minimum safe standard, according to those behind the research.

It suggests that savings made from shorter hospital stays and fewer readmissions were double the cost of hiring more staff.

The researchers behind the study noted that, despite some evidence that more nurses in hospitals could benefit patient safety, similar policies have not been widely implemented across the globe.

This they said was partly due to a previous absence of data on the long-term effects and costs, as well as limited staffing resources.

In recent years, Scotland, Wales, and Ireland have mandated numbers of patients per nurse, but strategies to improve nursing levels remains debated worldwide, they added.

In 2016, 27 public hospitals in Queensland were required to instate a minimum of one dedicated nurse for every four patients during day shifts and one for every seven patients for night shifts.

The research team collected data from those 27 Queensland hospitals that instated ratios and from 28 other hospitals in the state that did not, at baseline in 2016 and at follow-up in 2018.

Only nurses in direct contact with adult patients in medical-surgical wards were included, with data from patients in birthing suites and psychiatric units not assessed in the study.

Researchers used patient data to assess demographics, diagnoses, and discharge details for patients, as well as length of hospital stay.

This data was then linked to death records for 30 days following discharge, and to readmissions within seven days of discharge.

The researchers also surveyed nurses in each hospital to ask about the numbers of bedside nurses and patients on their most recent shift.

“These lessons should be considered in the context of a broad workforce strategy”

Amanda Ullman and Patricia Davidson

The responses were used to establish the numbers of nurses per patient and then averaged across wards and hospitals. Responses were received from 8,732 nurses in 2016, and 8,278 in 2018.

The study includes baseline data for 231,902 patients, and for 257,253 patients after the policy was brought in.

Comparison hospitals had no change in staffing, with six patients per nurse in 2016 and the same ratio of 1:6 in the follow-up period in 2018.

Intervention hospitals averaged five patients per nurse at baseline in 2016, with a reduction to four per nurse after the policy implementation.

To compare outcomes over time, the researchers estimated the odds of dying within 30 days of admission, of being readmitted within seven days of discharge, and the additional length of stay.

They found that the chance of death rose between 2016 and 2018 by 7% in hospitals that did not implement the policy and fell by 11% in hospitals that did implement the policy.

The chances of being readmitted increased by 6% in the comparison hospitals over time, but stayed the same in hospitals that implemented the policy.

Between 2016 and 2018, the length of stay fell by 5% in the hospitals that did not implement the policy, and by 9% in hospitals that did.

Further analysis found that when nurse workloads improved by one less patient per nurse, the chance of death and readmissions fell by 7%, and the length of hospital stay dropped by 3%.

The researchers estimated there could have been 145 more deaths, 255 more readmissions and 29,222 additional days in hospital in the 27 that implemented the policy from 2016 to 2018.

To calculate the financial impact, the researchers estimated the cost of funding the 167 extra staff needed to reduce workload by one patient per nurse at around £18,295,000 in the first two years.

“Patients cannot afford for the government to keep ducking this issue”

Pat Cullen

They further estimated that preventing readmissions and reducing lengths of stay resulted in an approximate saving of £38,336,336 in the 27 hospitals across the two years following the mandate.

Lead study author Professor Matthew McHugh, from the influential University of Pennsylvania School of Nursing, said: “Our findings plug a crucial data gap that has delayed a widespread roll-out of nurse staffing mandates.

“Opponents of these policies often raise concerns that there is no clear evaluation of policy, so we hope that our data convinces people of the need for minimum nurse-to-patient ratios by clearly demonstrating that quality nursing is vital to patient safety and care.”

Fellow author Professor Patsy Yates, of the Queensland University of Technology School of Nursing, said: “Part of the reluctance to bring in a minimum nurse-patient ratio mandate from some policy-makers is the expected rise in costs from increased staffing.

“Our findings suggest that this is short-sighted and that the savings created by preventing readmissions and reducing length of stay were more than twice the cost of employing the additional nurses needed to meet the required staffing levels — a clear return on investment.

“Often, policy-makers are concerned about whether they can afford to implement such a policy,” she said. “We would encourage governments to look at these figures and consider if they can afford not to.”

Writing in a linked Comment, Professor Amanda Ullman, from the University of Queensland, and Professor Patricia Davidson, from the University of Wollongong, said the study had “important lessons in what it takes to ensure patient safety”.

“These lessons should be considered in the context of a broad workforce strategy,” they said. “Building a robust nursing workforce is inextricably linked to patient outcomes and should be central to health services planning.”

Responding to findings, Pat Cullen, acting general secretary and chief executive at the Royal College of Nursing, said: “Every time the nurse number drops, mortality increases.

“That’s how critical we are to safe patient care,” she said. “This study adds to the known evidence for this from the UK.

“There are tens of thousands of unfilled nurse jobs right now and our new standards set out for government and the NHS a picture of what safe patient care should look like,” she added.

“Patients cannot afford for the government to keep ducking this issue. Accountability for workforce planning must be included in the forthcoming legislation for NHS and care services in England.”