JAC Advance Access originally published online on September 1, 2008
Journal of Antimicrobial Chemotherapy 2008 62(6):1422-1429; doi:10.1093/jac/dkn373
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Original research |
Impact of routine surgical ward and intensive care unit admission surveillance cultures on hospital-wide nosocomial methicillin-resistant Staphylococcus aureus infections in a university hospital: an interrupted time-series analysis
1 Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany 2 Institute of Hygiene and Environmental Medicine, Charité—University Medicine Berlin, Hindenburgdamm 27, D-12203 Berlin, Germany
Received 29 April 2008; returned 25 May 2008; revised 17 July 2008; accepted 8 August 2008
* Corresponding author. Tel: +49-511-532-3675; Fax: +49-511-532-8174; E-mail: chaberny.iris{at}mh-hannover.de
Objectives: To determine whether a routine admission screening in surgical wards and intensive care units (ICUs) was effective in reducing methicillin-resistant Staphylococcus aureus (MRSA) infections—particularly nosocomial MRSA infections—for the whole hospital.
Methods: The study used a single-centre prospective quasi-experimental design to evaluate the effect of the MRSA screening policy on the incidence density of MRSA-infected/nosocomial MRSA-infected patients/1000 patient-days (pd) in the whole hospital. The effect on incidence density was calculated by a segmented regression analysis of interrupted time series with 30 months prior to and 24 months after a 6 month implementation period.
Results: The MRSA screening policy had a highly significant hospital-wide effect on the incidence density of MRSA infections. It showed a significant change in both level [–0.163 MRSA-infected patients/1000 pd, 95% confidence interval (CI): –0.276 to –0.050] and slope (–0.01 MRSA-infected patients/1000 pd per month, 95% CI: –0.018 to –0.003) after the implementation of the MRSA screening policy. A decrease in the MRSA infections by 57% is a conservative estimate of the reduction between the last month before (0.417 MRSA-infected patients/1000 pd) and month 24 after the implementation of the MRSA screening policy (0.18 MRSA-infected patients/1000 pd). Equivalent results were found in the analysis of nosocomial MRSA-infected patients/1000 pd.
Conclusions: This is the first hospital-wide study that investigates the impact of introducing admission screening in ICUs and non-ICUs as a single intervention to prevent MRSA infections performed with a time-series regression analysis. Admission screening is a potent tool in controlling the spread of MRSA infections in hospitals.
Keywords: MRSA , screening policies , infection control , prevention measures , reduction