David GreenLead Nurse Infection ControlBradford Teaching Hospitals

Does hospital cleanliness correlate with MRSA bacteraemia rates?

Green D, Wigglesworth N, Keegan T, and Wilcox M (JHI Oct 2006)

Background

• Possible over emphasis from govt regarding hospital cleanliness

• “Cleanliness and the control of infection at the heart of inspection regimes” (John Reid: Towards cleaner hospitals and lower rates of infection DH 2003)

• Same emphasis being given by political parties in the election campaign in May 2005

Introduction

• MRSA rates vary 100 fold between different countries in Europe.

• <1% in northern Europe, >40% in western and southern Europe.

• MRSA rates vary 11 fold in NHS general and specialist trusts

• Each hospital trust is subject to annual inspection of its cleanliness (PEAT)

Methodology• Is there a correlation between hospital

cleanliness (as measured by PEAT) and MRSA bacteraemia rates?

• PEAT data was sources from DH “Clean Hospitals” website

• In 2001 to 2003 a three point PEAT score used by the DH, in 2004 a five point score was used

• An average score was assigned to each trust, weighted for the number of beds in each hospital

Methodology

• Data on MRSA bacteraemia was sourced from DH website

• Expressed as number of bacteraemias per 1000 bed days

Statistical Analysis

• Is there significant difference in MRSA bacteraemia rates between different trusts?

• Is there a significant change in PEAT scores

• Is there a correlation between MRSA bacteraemia rates and PEAT scores for 2001-03 and 2004?

Results • In 2001- 03 PEAT scores varied

significantly between different hospitals (P=<0.001)

• In 2001- 04 PEAT scores improved significantly (P=<0.001)

• MRSA bacteraemia rates varied significantly between trusts (P=<0.001)

• No significant difference in MRSA bacteraemia rates in 2001 compared with 2005 (P=0.443)

Results

• No correlation between average MRSA bacteraemia rates and weighted average PEAT scores (P=0.05) with the exception of single speciality trusts in 2004-05

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

Apr 01-Mar 02 Apr 02-Mar 03 Apr 03-Mar 04 Apr 04-Mar 05

Ave

rage

Rat

e

April 01 – March 02 April 02 – March 03 April 03 – March 04 April 04 – March 05

0.16 0.16 0.17 0.16

Average MRSA Rate

Average MRSA bacteraemia rates per NHS trust April 01 to Mar 05

Average Weighted PEAT Scores per trust April 01 to Mar 04

April 01 – March 02 April 02 – March 03 April 03 – March 04

1.50 1.37 1.23

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

Apr 01-Mar 02 Apr 02-Mar 03 Apr 03-Mar 04

Ave

rage

Rat

e

Discussion

• Not possible to show a consistent relationship between hospital cleanliness as measured by PEAT and MRSA bacteraemia rates

• Despite PEAT scores improving significantly, MRSA bacteraemia rates have not changed significantly from 2001 to 2005

Why?

• There may be no relationship between the environment and MRSA incidence

• There may be a relationship but variables have obscured it (unlikely given size of data set)

• PEAT scores may not accurately reflect hospital cleanliness or MRSA bacteraemia does not reflect the overall burden of MRSA in hospitals

Conclusion

• No direct link between hospital environmental cleanliness measured by PEAT and the risk of MRSA bacteraemia

• Programs that target hospital cleanliness alone are unlikely to succeed in reducing MRSA

• A high standard of hospital cleanliness is a goal worth achieving but continual linking of MRSA and cleanliness is not helpful