• First UK study to link individual patient outcomes to nursing care and staffing levels
  • Patients were at increased risk of death when there was low staffing and high temporary staffing
  • High levels of admissions per nurse were associated with increased risk

New research at an NHS hospital has shown a “direct link” between the care individual patients receive from nurses and their risk of death due to low staffing levels.

Emerging findings from the study, the first of its kind in the UK to link nursing care to the outcomes of individual patients, also demonstrate a link between the risk of death and the use of temporary staff, as well as increased risks for patients when wards have high numbers of admissions.

Professor Peter Griffiths, lead investigator of the study funded by the National Institute for Health Research, told HSJ: “This is the first time we have been able to show direct individual links between the nursing care on the ward that these patients were experiencing and their outcomes on an individual basis. There has only been one similar study in the US.

“It means we can be much more confident that low staffing is what is causing these adverse effects. We can’t be 100 per cent certain but this can’t be dismissed as easily as other studies. It is much more likely to be a causal link.”

The project looked at staffing levels across 32 general medical and surgical wards at one NHS hospital between April 2012 and March 2015. More than 107,000 patients and almost 700,000 staff shifts were analysed using data from rostering systems and electronic observations, with the number of care hours per patient per day calculated and compared to mortality risks.

Key findings from the research were:

  • When patients were exposed to low nursing hours during the first five days of their hospital stay, their risk of death significantly increased. For each day of low registered nurse staffing, the risk of death was increased by 3 per cent.
  • Patients whose stay included days of high patient turnover in terms of admissions per nurse were associated with a 5 per cent increase in the risk of death.
  • High levels of temporary staffing on the ward was associated with increased risk of death. When 1.5 or more nurse hours per patient day were provided by temporary staff the risk of death increased by 12 per cent.
  • Each additional nurse hour per patient day was associated with a 2 per cent decrease in the chance of vital sign observations being missed.

Professor Griffiths, from the University of Southamoton, said the study “provides important confirmation that the observed associations may be causal”. He added: “We have demonstrated that when wards experience an unusually high number of admissions per registered nurse the hazard of death is also increased, suggesting that the work involved may exceed capacity.”

He said this was a key warning for NHS leaders as they seek to reduce lengths of stay and increase the throughput of patients – an objective cited by many trusts and sustainability and transformation plans as a measure of efficiency.

Professor Griffiths said: “We have more nurses working in NHS hospitals than we did 10 years ago, which is good, but the work they are doing with each patient has also increased as stays become shorter and patient turnover has increased. Here is something showing the consequences of not increasing the workforce to match this higher intensity.

“If you are going to run the system hot, meaning more acutely ill patients having shorter lengths of stay, you need to increase the staffing in a commensurate way rather than see it as an efficiency and a way of doing more with the same staff.”

Professor Griffiths said the study was due to be published later this year. It will add to a growing body of NHS based research showing links between registered nurse staffing and patient outcomes.

In December, a study by Professor Alison Leary found a “calculable” link between nurse numbers and patient outcomes, including 40 separate correlations with staffing levels.