“Overworked nurses ‘put patients at greater risk of infection’,” is the headline in the Daily Mail.
The news is based on a survey from the US that looked at a combination of:
- the nurse to patient ratio in 161 hospitals in Pennsylvania
- how many cases of two common hospital-acquired infections occurred in these hospitals
- reported feelings of ‘burnout’ by nurses working in those hospitals
There is no precise clinical definition of ‘burnout’, but some experts have described it as a combination of emotional exhaustion and detachment, and a feeling that a person is not performing well in their job.
The researchers estimated that for each additional patient assigned to a nurse, there was roughly one additional infection per 1,000 patients.
This appears to be a well conducted study that raises interesting questions about the impact of staffing levels on patient care. However, this cross-sectional analysis can’t prove causation (direct cause and effect). The rate of hospital-acquired infections may be the result of complex causes, so claiming there is a direct link between ‘burnout’ and rates of infection is arguably oversimplistic.
There are also several reasons why you can’t assume that the same findings translate from the US to the UK. Many factors that may affect job satisfaction vary between the US and the UK, including working hours, wages and average travel to work.
Where did the story come from?
The study was carried out by researchers from the University of Pennsylvania School of Nursing. It was funded by the US National Institute of Nursing Research, National Institutes of Health. It was published in the peer-reviewed American Journal of Infection.
This story was covered well by the Daily Mail, but the headline did not make clear that the figures were based on American research and not on nurses working in the NHS.
What kind of research was this?
This was a cross-sectional study. It aimed to determine whether nurse staffing levels and nurse-reported job-related burnout were associated with the incidence of catheter-associated urinary tract infections and surgical site infections, which are two of the most common hospital-acquired infections.
Cross-sectional studies have limitations because they can’t determine what happened first. For example, it is unclear whether the nurses were feeling burnt out, which led to an increase in hospital-acquired infections, or whether the increase in infections led to burnout. There may also have been many other factors that led to increased numbers of hospital-acquired infections, which these surveys may not have been able to take into account.
What did the research involve?
The researchers reportedly used information from a variety of sources – from the Pennsylvania Health Care Cost Containment Council, the American Hospital Association Annual Survey and a 2006 survey of a sample of nurses. The responses from the survey of more than 7,000 nurses from 161 hospitals in Pennsylvania were used to determine job-related burnout. The nurses were reported to have completed the Maslach Burnout Inventory – Human Services Survey (MBI-HSS). The survey included 22 items on job-related attitudes, which were subdivided into emotional exhaustion, depersonalisation and personal accomplishment. Emotional exhaustion is said to be the key component related to burnout syndrome and, therefore, job-related burnout was determined by analysing the emotional exhaustion scale on the MBI-HSS.
The researchers looked at the effect that nurse staffing levels and job-related burnout reported by nurses had upon catheter-associated urinary tract infections and surgical site infections. When looking to see if there was an association, the researchers took into account the age of the nurses, how many years experience they had, whether the hospital was a teaching hospital, what procedures the hospital performed, how big the hospital was and how ill the patients were. They then calculated the number of infections that could be avoided and the money that could be saved if job-related burnout in nurses was reduced.
What were the basic results?
The results were as follows:
- more than one-third of the nurses that responded to the survey fulfilled the criteria for healthcare personnel burnout (an emotional exhaustion score of 27 or greater)
- the average patient load per nurse was 5.7 patients
- on average, there were nine catheter-associated urinary tract infections across hospitals per 1,000 patients, and five surgical site infections per 1,000
- for each additional patient assigned to a nurse, there was one additional catheter-associated urinary tract infection per 1,000 patients and one surgical site infection per 1,000 patients
- for every 10% increase in nurses with high burnout in a hospital there was one additional catheter-associated urinary tract infection and two surgical site infections per 1,000 patients
- when nurse burnout and staffing were considered together, the staffing effect was no longer significant after adjusting for nurse burnout – this means that infection rate differences between hospitals of differing staffing levels could be attributed to nurse burnout
- the researchers also calculated the savings that could be made in the US if nurse burnout rates were reduced and found that reducing nurse burnout rates to 10% would prevent approximately 4,160 infections and save $41 million annually in Pennsylvania
How did the researchers interpret the results?
The researchers concluded that “healthcare facilities can improve nurse staffing and other elements of the care environment and alleviate job-related burnout in nurses at a much lower cost than those associated with healthcare-associated infections”. They continue by saying that “by reducing nurse burnout, we can improve the well-being of nurses while improving the quality of patient care”.
This cross-sectional study found that, in Pennsylvania, having more patients per nurse, or having a higher proportion of nurses with job-related burnout was associated with an increased number of two of the most common hospital-acquired infections – catheter-associated urinary tract infections and surgical site infections. Higher caseloads may lead to burnout
However, the study design means that the results cannot prove that burnout or low staffing levels directly caused an increase in hospital-acquired infections. There may be many other factors involved in the cause of hospital-acquired infections which these surveys may not have been able to take into account. In addition, the timeline of events cannot be determined. For example, it is unclear whether nurses were feeling burnt out, which resulted in an increase in hospital-acquired infections or whether an increase in infections led to burnout.
The results of the survey may also not necessarily apply to nurses working in the NHS. This is because many factors that may affect job satisfaction vary between the US and the UK, including working hours, wages and average travel to work.
Overall, the reports raise an important issue, but no firm conclusions can be made about how or whether nurse staffing levels or overwork are associated with hospital-acquired infections.
Analysis by Bazian
Edited by NHS Website
Links to the headlines
Daily Mail, 30 July 2012
Links to the science
American Journal of Infection Control. Published online July 29 2012
(PDF, 1.70Mb). 2010