Results of the first three and a half years of the Department of Health's mandatory methicillin resistant Staphylococcus aureus (MRSA) surveillance system in acute Trusts in England

• An MRSA bacteraemia report is made when MRSA is detected in a blood sample by culture.
• KHO3 bed days data are statistics based on an approximate count of the average number of occupied hospital beds in a trust each day (bed days). These data are collated by the Department of Health.
• The MRSA rates for each Trust represent the average number of MRSA bacteraemia reports per 1000 bed days, for that 6 month period.
• The first six surveillance periods from April 2001 to March 2004, have been reanalysed using the appropriate year's bed occupancy data. This now is intended to represent a final dataset for years 2001 to 2003.
• The last surveillance period in this series is for April 2004 to September 2004 and uses the only available KHO3, namely that for the previous year 2003-04. These 2004 rates will be regarded as provisional and will be updated with the appropriate KHO3 data when available.
• In a short period of time such as six months, there may be few MRSA bacteraemia reports for a given Trust. In small trusts, changes of one or two bacteraemia reports can cause large fluctuations in MRSA rate, which can be misleading when making comparisons of values or ranks.
• Confidence intervals are used to give an idea as to the uncertainty about the estimated MRSA bacteraemia rate. It is expected that some variation between six monthly MRSA rates will occur due to chance alone. For any given rate, we can loosely say that there is a 95% chance that the "true" rate lies within its 95% confidence interval.

Figure 1: MRSA bacteraemia rates in England by Trust type from April 2001 to September 2004 (PDF, 11 KB)

 This graph represents average MRSA bacteraemia rates per 1000 bed days for General Acute, Specialist and Single Specialty Trusts. The error bars show the 95% confidence intervals for each rate. In every six month period, on average, Specialist Trusts have the highest MRSA rates and Single Specialty Trusts have the lowest rates.

Figure 2: Number of MRSA bacteraemia reports in England from April 2001 to September 2004 (PDF, 92 KB)

 This graph shows the number of MRSA bacteraemia reports for General Acute, Specialist and Single Specialty Trusts, coded by colour. The size of each bar gives a measure of the total number of MRSA reports for each six month period.

Figure 3: MRSA bacteraemia rates numbers in England for each six month period between April 2001 and September 2004 (PDF, 94 KB)

Each bar on this graph represents the number of MRSA bacteraemia reports for a particular six month period, which can be read from the left hand vertical axis. The MRSA rates are plotted as points which can be read from the right hand vertical axis, with error bars showing the confidence intervals for each rate.

Figure 4: Regional comparison of the number of MRSA bacteraemia reports for each April to September period between 2001 and 2004 (PDF, 94 KB)

This graph compares the number of MRSA bacteraemia reports in April to September periods of each year between 2001 and 2004. The columns in the front/foreground are for the most recent six month period.

Figure 5: Regional comparison of the number of MRSA bacteraemia reports for every six month period between 2001 and 2004 (PDF, 112 KB)

This graph can be used to compare the number of MRSA bacteraemia reports in consecutive six month periods between 2001 and 2004. The columns in the front/foreground are for the most recent six month period.

To see the data broken down by NHS Trust please go to the Department of Health website at http://www.dh.gov.uk/Home/fs/en

Last reviewed: 9 April 2009