High monthly turnover rates of nurses and senior doctors are associated with higher deaths for emergency patients admitted to NHS hospitals in England, finds a study published by The BMJ today.
The findings suggest that efforts to reduce staff turnover may improve patient care and hospital quality, say the researchers.
The retention of healthcare workers is critical for the provision of patient care, as acknowledged by the NHS long term workforce plan. Previous research has investigated the association between clinical staff turnover and increased organisational costs but, so far, studies have not been able to measure both staff turnover and its effect on patient outcomes at a national level.
To address this, researchers set out to investigate the association between monthly turnover rates of nurses and senior doctors with deaths and unplanned readmissions for patients admitted to hospital over nine years.
Their findings are based on yearly records for 236,000 nurses; 41,800 senior doctors (hospital consultants and specialty associated doctors) and 8.1 million patients admitted to 148 NHS acute hospital trusts in England from 1 April 2010 to 30 March 2019.
The main outcomes of interest were risk of death from any cause within 30 days of hospital admission, and risk of unplanned readmission within 30 days of discharge after elective hospital treatment.
After accounting for patient age, sex, and pre-existing conditions, the researchers found that a one standard deviation increase in the monthly turnover rate for nurses - equivalent to about 20 nurses quitting the hospital trust - was associated with 35 additional deaths per 100,000 admissions in a given month, equivalent to an extra 239 deaths per month across the 148 hospital trusts.
For senior doctors, a one standard deviation increase in the monthly turnover rate - equivalent to about seven senior doctors quitting the hospital trust - was associated with 14 additional deaths per 100,000 admissions in a given month, equivalent to an extra 96 deaths per month across the 148 hospital trusts.
Higher nurse turnover was linked to increased deaths for patients on surgical and general medicine wards, while higher turnover among senior doctors was linked to increased deaths in patients with infectious diseases and mental health disorders.
No statistically significant association was seen between staff turnover rates and deaths for non-emergency care patients, likely due to the higher risk of death in patients requiring emergency admission, note the authors.
They acknowledge that these are observational findings, so no firm conclusions can be drawn about causality, and they can't rule out the possibility that other unmeasured factors may have affected their results.
However, this was a large study which analysed nearly a decade of data across all acute NHS hospital trusts in England, and results were similar after further analyses to test the strength of the associations, suggesting that they are robust.
While further research is needed to investigate the mechanisms behind these associations, the authors suggest a pragmatic approach to reducing hospital staff turnover rates would be to focus on factors such as pay packages, staff engagement, and more favourable working conditions.
The government could also prioritise NHS sector pay rises for nurses because lower nurse turnover rates may actually carry higher returns to patient care and increasing retention of senior doctors, they add.
These findings highlight the importance of continuity of care, say researchers from Norway in a linked editorial.
They acknowledge that continuity is a major challenge for managers and policy makers, and say staff retention depends on several factors including a streamlined onboarding process, investment in personal and professional development and training, and a supportive leadership and work environment.
The message for hospital managers and policy makers is clear, they conclude. "High turnover of nurses and doctors suggests a potential risk for patients. Therefore, retention of healthcare staff should be a priority to improve continuity and quality of care for patients."
