Friday May 4 2012
Levels of MRSA and C. difficile infections in hospitals have fallen
A national hand hygiene campaign "cut superbug infections," according to BBC News. The BBC and other news outlets have reported the success of a hand-washing campaign in cutting infection rates in hospitals.
The headlines stem from a study of hand-washing practices at 187 NHS trusts in England and Wales between 2004 and 2008. The Clean Your Hands campaign was introduced in 2004 and this study looked at its effects.
Researchers examined purchases of alcohol hand rub and liquid soap by hospitals against trends of common hospital-acquired infections such as MRSA and Clostridium difficile (C. difficile). They found that the total amount of soap and alcohol gel being purchased by hospitals tripled across the four years of the study, from 22ml per patient per day to 60ml per patient per day. Over the same period, rates of MRSA more than halved and C. difficile infections fell by more than 40%.
Although the study demonstrates some associations between increased purchasing of alcohol gel or soap and reduced infection rates, it can’t prove that the campaign itself has influenced infection rates.
This is because the study doesn’t take into account factors such as how people are washing their hands, whether other infection-control practices are being followed or how antibiotics are being prescribed. Furthermore, not all infections have demonstrated a continual decline in rate over the period.
The researchers also pointed out that other national campaigns might have been beneficial too. Nevertheless, the study’s findings are promising and indicate that national campaigns to improve hand hygiene and reduce hospital-acquired infections can be useful.
Where did the story come from?
The study was carried out by researchers from University College London (UCL) Medical School and other institutions in the UK and was funded by the Patient Safety Research Programme and UCL. The study was published in the British Medical Journal.
The headline findings of the study were fairly well reported by most media outlets. However, the reports didn’t examine some of the study’s limitations, including the researchers’ untested assumption that bigger purchases of alcohol gel and liquid soap indicated improved hand hygiene within hospitals.
What kind of research was this?
This was a time-trend study that looked at rates of purchasing of alcohol hand rub and soap and reporting trends for healthcare-associated infections during a national hand-washing campaign that had been introduced across 187 NHS trusts. It aimed to examine associations between these purchasing rates and infection rates.
The study may indicate that the introduction of a hand-washing campaign could have influenced trends, but it can’t prove that the campaign itself has been directly responsible for any change in trend because other, unmeasured factors may have been involved.
For example, this study has based its analysis on the purchasing levels of alcohol hand rub and liquid soap. It can’t tell us how well hand-washing procedures or other infection-control practices are actually being followed.
Nevertheless, looking back at data in a time-trend study adds to the overall picture and evidence when examining the possible influences of the campaign.
What did the research involve?
The Clean Your Hands campaign was supported by the Department of Health (DH) and National Patient Safety Agency and was first introduced to NHS hospitals in England and Wales in 2004. The campaign involved:
- the provision of alcohol hand rub at every patient’s bedside
- distribution of posters reminding healthcare workers to clean their hands
- regular audit and feedback of compliance
- the provision of materials empowering patients to remind healthcare workers to clean their hands
The trusts were instructed to order soap and alcohol hand rub through the central NHS supply agencies to ensure that all products met efficacy, safety and acceptability standards. Six hospital trusts received the campaign in December 2004 and the remaining 181 trusts by the end of June 2005. The campaign was then refreshed at the end of June 2006, and re-launched with new posters in October 2007.
The researchers were particularly interested in looking at the periods from July 2004 to December 2004 (before the introduction of the campaign); January to June 2005 (during the introduction of the campaign) and July 2005 to June 2008 (following the introduction of the campaign).
For each individual trust, researchers looked at monthly procurement rates of alcohol hand rub and liquid soap. For infection rates, they looked at the national reporting scheme database held by the Health Protection Agency to identify quarterly rates of hospital-acquired MRSA blood infections, C. difficile infections (only in people aged over 65) and other Staphylococcus aureas infections.
When analysing the association between alcohol gel and soap purchasing rates and infection rates, the researchers did take into account other factors that could have influenced both of these things, aside from the campaign. These factors included the announcement of the MRSA target, the publication of the Health Act 2006, the Saving Lives campaign and trust visits by DH improvement teams.
What were the basic results?
The researchers looked at 187 hospital trusts in England and Wales. Overall procurement of both liquid soap and alcohol hand rub tripled across the four years of the study, from 22ml to nearly 60ml per patient per bed day. (One bed day equates to one person occupying a hospital bed for a day.)
Meanwhile, rates of MRSA fell from 1.88 cases per 10,000 bed days at the start of the study period to 0.91 cases per 10,000 bed days at the end of the study period.
C. difficile infection rates fell from 16.75 to 9.49 cases per 10,000 bed days. However, there was no clear trend in the rates of C. difficile infection, and infection rates between 2004 and 2008 continued to fluctuate with the seasons.
Rates of Staphylococcus aureas did not show a decrease: they rose from 2.67 cases per 10,000 bed days at the start of the period to a peak of 3.23 in 2007, and then declined to 3 cases per 10,000 bed days at the end of the study period in 2008.
After adjusting for other factors, the researchers calculated that the increased purchase of soap was associated with reduced C. difficile infection throughout the study. Increased procurement of alcohol hand rub was associated with reduced MRSA blood infection in the last 12 months of the study. These were the only significant associations found.
In some analyses, the researchers found that a rise in procurement of alcohol gel or soap was associated with a rise in Staphylococcus aureas infection rates.
When they looked at the influence of the other campaigns and interventions, the researchers found that publication of the Health Act in 2006 was strongly associated with reduced MRSA blood infections and C. difficile infection rates. They found that trust visits by DH improvement teams were also associated with reduced MRSA blood infections and C. difficile infection rates for at least six months after each visit.
How did the researchers interpret the results?
The authors concluded that the Clean Your Hands campaign was associated with sustained increases in hospital procurement of alcohol rub and soap. They said their findings suggest that the campaign has played an important role in reducing rates of certain hospital-acquired infections and highlighted that “national interventions for infection control undertaken in the context of a high profile political drive” can be effective.
This is a valuable study that has attempted to examine the effect of the Clean Your Hands campaign in improving hand hygiene and reducing the rate of hospital-acquired infections.
The study has acquired reliable data on soap and alcohol gel procurement rates, along with infection rates, and has demonstrated some associations between increased procurement and a decline in the rate of hospital-acquired MRSA blood infection and Clostridium difficile infections.
However, on its own, the study can’t prove that the Clean Your Hands campaign has influenced infection rates. The study was only able to use purchases of alcohol gel or liquid soap as an indication of hand hygiene, and although this is an objective measure it doesn't tell us whether people are following correct hand hygiene practices and performing hand sanitisation at the correct times (for example, before and after contact with each patient). It also can’t tell us whether other infection-control practices are being followed, or about other things that may influence infection rates such as antibiotic prescription.
It is noteworthy that not all infections were shown to have declined in rate over the period. For example, C. difficile rates have continued to demonstrate quite marked seasonal variation between 2004 and 2008. Furthermore, the increased procurement of soap or alcohol gel was not always associated with decreased infection rates throughout the study period, and in some analyses the opposite was observed – increased procurement was associated with increased infection rate.
The study did adjust for other factors that could have influenced both purchasing rates and infection rates, and found that some of these factors also had an effect. These included the publication of the Health Act 2006 and trust visits by Department of Health improvement teams.
Nevertheless, the study’s findings were promising and indicated that national campaigns to improve hand hygiene and reduce hospital-acquired infections are likely to be useful.