Relying on agency nurses carries patient safety risks – study

The study, published in the journal BMJ Quality and Safety, looked into the impact of nurse understaffing on mortality in patients.

“It shows that concerns over understaffing are valid and backed up by the empirical evidence"

Ben Zaranko

Researchers used data from electronic staff rosters from 2017 to measure nurse understaffing, defined as the shortfall between planned staffing for a shift, and the actual staffing on the day.

The researchers then compared daily levels of understaffing of nurses to mortality rates in adult patients across 53 acute hospital wards in a single NHS trust in England over a 12 month period.

They found a significantly increased risk of death in patients on wards where there was a shortfall in the number of registered nurses on shift. On days when two or more planned registered nursing shifts went unfilled there was a significant increase in mortality in patients on the ward.

Mortality increased in line with the degree of understaffing. Teams lacking 16 hours-worth of registered nurse care in one shift saw a 23% increase in mortality, while those lacking 24 hours saw a 37% increase.

The study also looked into the impact on patient mortality of the experience and seniority of the nurses on a team, and compared the different impact that a nurse employed by the trust might have compared to an agency nurse.

The researchers found that adding an extra 12 hour shift from a registered nurse to the average nursing team reduced the odds of a patient on the ward dying during that hospital visit by around 9.6%.

However, this benefit was only seen if the nurse was permanently employed by the trust working either a regular shift or overtime via the bank. No benefit in reduced mortality was seen if the shift was filled by an agency nurse.

There was also no association found between lower levels of healthcare support worker staffing and increased patient mortality.

Nurse seniority was found to be an important factor in terms of patient safety benefits.

Adding an additional senior nurse, at pay band 7 or 8 under the Agenda for Change contract, to a nursing team reduced the odds of a patient dying by twice as much as adding a nurse at pay band 5.

“While agency staff have an important role to play, this study, likes others, shows that there is an important balance to be struck – for patients’ sake"

Lisa Elliott

The researchers concluded that this shows the “significant value” of senior, more experienced nurses who provide team leadership.

Senior research economist at the Institute for Fiscal Studies in London, Ben Zaranko, who was the lead author on the study, told the Nursing Times that the study showed concerns over understaffing were “valid”.

He said: “Our research clearly demonstrates the important role played by nurses, and in particular experienced nurses, in improving patient outcomes and provides new evidence of the negative impacts of short-staffing.

“It shows that concerns over understaffing are valid and backed up by the empirical evidence.”

The study was led by researchers from the Institute for Fiscal Studies but also included experts from the Health Foundation and Imperial College Healthcare NHS Trust.

Also among the study authors was respected nurse academic Professor Anne Marie Rafferty, from the Florence Nightingale Faculty of Nursing Midwifery and Palliative Care at King’s College London.

Responding to the findings, Lisa Elliott, the Royal College of Nursing’s deputy director for workforce, professional practice, and quality, said: “This research highlights the negative impact that not having enough experienced or permanent nursing staff can have on care and patient safety.”

She accused the government of relying on agency staff to fill workforce gaps rather than focusing on long-term measures to boost nurse recruitment and retention.

“While agency staff have an important role to play, this study, likes others, shows that there is an important balance to be struck – for patients’ sake – and ministers’ failure to grip the situation, or even acknowledge it, means we’re heading in completely the wrong direction,” warned Ms Elliot.