Fidelma A. Magee

Modelling the impact of antibiotic use and infection control practices on the incidence of hospital-acquired methicillin-resistant Staphylococcus aureus: a time-series analysis

OBJECTIVES Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen worldwide. A wide range of factors have been suggested to influence the spread of MRSA. The objective of this study was to evaluate the effect of antimicrobial drug use and infection control practices on nosocomial MRSA incidence in a 426-bed general teaching hospital in Northern Ireland. METHODS The present research involved the retrospective collection of monthly data on the usage of antibiotics and on infection control practices within the hospital over a 5 year period (January 2000-December 2004). A multivariate ARIMA (time-series analysis) model was built to relate MRSA incidence with antibiotic use and infection control practices. RESULTS Analysis of the 5 year data set showed that temporal variations in MRSA incidence followed temporal variations in the use of fluoroquinolones, third-generation cephalosporins, macrolides and amoxicillin/clavulanic acid (coefficients = 0.005, 0.03, 0.002 and 0.003, respectively, with various time lags). Temporal relationships were also observed between MRSA incidence and infection control practices, i.e. the number of patients actively screened for MRSA (coefficient = -0.007), the use of alcohol-impregnated wipes (coefficient = -0.0003) and the bulk orders of alcohol-based handrub (coefficients = -0.04 and -0.08), with increased infection control activity being associated with decreased MRSA incidence, and between MRSA incidence and the number of new patients admitted with MRSA (coefficient = 0.22). The model explained 78.4% of the variance in the monthly incidence of MRSA. CONCLUSIONS The results of this study confirm the value of infection control policies as well as suggest the usefulness of restricting the use of certain antimicrobial classes to control MRSA.

An evaluation of the impact of antibiotic stewardship on reducing the use of high-risk antibiotics and its effect on the incidence of Clostridium difficile infection in hospital settings

OBJECTIVES To evaluate the impact of a high-risk antibiotic stewardship programme on reducing antibiotic use and on hospital Clostridium difficile infection (CDI) incidence rates. A secondary objective was to present the possible utility of time-series analysis as an antibiotic risk classification tool. METHODS This was an interventional, retrospective, ecological investigation in a medium-sized hospital over 6.5 years (January 2004 to June 2010). The intervention was the restriction of high-risk antibiotics (second-generation cephalosporins, third-generation cephalosporins, fluoroquinolones and clindamycin). Amoxicillin/clavulanic acid and macrolides were classified as medium-risk antibiotics based on time-series analysis findings and their use was monitored. The intervention was evaluated by segmented regression analysis of interrupted time series. RESULTS The intervention was associated with a significant change in level of use of high-risk antibiotics (coefficient -17.3, P < 0.0001) and with a borderline significant trend change in their use being reduced by 0.156 defined daily doses/100 bed-days per month (P = 0.0597). The reduction in the use of high-risk antibiotics was associated with a significant change in the incidence trend of CDI (P = 0.0081), i.e. the CDI incidence rate decreased by 0.0047/100 bed-days per month. Analysis showed that variations in the incidence of CDI were affected by the age-adjusted comorbidity index with a lag of 1 month (coefficient 0.137051, P = 0.0182). Significant decreases in slope (coefficient -0.414, P = 0.0309) post-intervention were also observed for the monitored medium-risk antibiotics. CONCLUSIONS The restriction of the high-risk antibiotics contributed to both a reduction in their use and a reduction in the incidence of CDI in the study site hospital. Time-series analysis can be utilized as a risk classification tool with utility in antibiotic stewardship design and quality improvement programmes.

Clinical and economic impact of contaminated blood cultures within the hospital setting

Blood cultures have an important role in the diagnosis of serious infections, although contamination of blood cultures (i.e. false-positive blood cultures) is a common problem within the hospital setting. The objective of the present investigation was to determine the impact of the false-positive blood culture results on the following outcomes: length of stay, hotel costs, antimicrobial costs, and costs of laboratory and radiological investigation. A retrospective case-control study design was used in which 142 false-positive blood culture cases were matched with suitable controls (patients for whom cultures were reported as true negatives). The matching criteria included age, comorbidity score and month of admission to the hospital. The research covered a 13-month period (July 2007 to July 2008). The findings indicated that differences in means, between cases and controls, for the length of hospital stay and the total costs were 5.4 days [95% CI (confidence interval): 2.8-8.1 days; P<0.001] and £5,001.5 [

Multihospital Outbreak of Clostridium difficile Ribotype 027 Infection: Epidemiology and Analysis of Control Measures

7,502.2; 95% CI: £3,283.9 (

A point prevalence survey of antibiotic prescriptions: benchmarking and patterns of use

4,925.8) to £6,719.1 (

An Evaluation of the Impact of a Single-Dose Intravenous Immunoglobulin Regimen in the Treatment of Clostridium difficile Infections

10,078.6); P<0.001], respectively. Consequently, and considering that 254 false-positive blood cultures had occurred in the study site hospital over a one-year period, patients with false-positive blood cultures added 1372 extra hospital days and incurred detrimental additional hospital costs of £1,270,381 (

Impact of an enhanced antibiotic stewardship on reducing methicillin-resistant Staphylococcus aureus in primary and secondary healthcare settings

1,905,572) per year. The findings therefore demonstrate that false-positive blood cultures have a significant impact on increasing hospital length of stay, laboratory and pharmacy costs. These findings highlight the need to intervene to raise the standard of blood-culture-taking technique, thus improving both the quality of patient care and resource use.

Tackling the problem of blood culture contamination in the intensive care unit using an educational intervention

OBJECTIVE To report a large outbreak of Clostridium difficile infection (CDI; ribotype 027) between June 2007 and August 2008, describe infection control measures, and evaluate the impact of restricting the use of fluoroquinolones in controlling the outbreak. DESIGN Outbreak investigation in 3 acute care hospitals of the Northern Health and Social Care Trust in Northern Ireland. INTERVENTIONS Implementation of a series of CDI control measures that targeted high-risk antibiotic agents (ie, restriction of fluoroquinolones), infection control practices, and environmental hygiene. RESULTS A total of 318 cases of CDI were identified during the outbreak, which was the result of the interaction between C. difficile ribotype 027 being introduced into the affected hospitals for the first time and other predisposing risk factors (ranging from host factors to suboptimal compliance with antibiotic guidelines and infection control policies). The 30-day all-cause mortality rate was 24.5%; however, CDI was the attributable cause of death for only 2.5% of the infected patients. Time series analysis showed that restricting the use of fluoroquinolones was associated with a significant reduction in the incidence of CDI (coefficient, -0.054; lag time, 4 months; P = .003). CONCLUSION These findings provide additional evidence to support the value of antimicrobial stewardship as an essential element of multifaceted interventions to control CDI outbreaks. The present CDI outbreak was ended following the implementation of an action plan improving communication, antibiotic stewardship, infection control practices, environmental hygiene, and surveillance.

A modified method for measuring antibiotic use in healthcare settings: implications for antibiotic stewardship and benchmarking

AIM The aim of the study was to assess current patterns of antibiotic prescribing and the impact of a hospital antibiotic policy on these practices. METHODS The study involved collecting information regarding hospitalized patients utilizing the ESAC audit tool. RESULTS In the study site hospital, the use of the restricted agents was low whilst the use of the non-restricted agents was high. Compliance with the hospital antibiotic guidelines was 70%. DISCUSSION The findings identified monitoring non-restricted antibiotics and compliance with guidelines as targets for quality improvements in our hospital. Point prevalence surveys may offer a simple method of monitoring antibiotic policies, thus, informing antibiotic stewardship.

A point prevalence survey of antibiotic use in four acute-care teaching hospitals utilizing the European Surveillance of Antimicrobial Consumption (ESAC) audit tool

Treatment of Clostridium difficile Infections • Author(s): Mamoon A. Aldeyab, PhD; James C. McElnay, PhD; Michael G. Scott, PhD; Elizabeth Davies, MB, BCH, BAO, FRCPath; Collette Edwards, BSc; Feras W. Darwish Elhajji, MSc; Geraldine Conlon, MSc; Fidelma A. Magee, BSc; Paul J. Barr, PhD; Mary P. Kearney, MB, BCH, BAO, FRCPath Source: Infection Control and Hospital Epidemiology, Vol. 32, No. 6 (June 2011), pp. 631-633 Published by: The University of Chicago Press on behalf of The Society for Healthcare Epidemiology of America Stable URL: http://www.jstor.org/stable/10.1086/660203 . Accessed: 18/05/2014 15:11