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.
OBJECTIVE
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 Practice Research Group, School of Pharmacy, Queen's University Belfast, BT9 7BL Belfast, Northern Ireland, UK. maldeyab02@qub.ac.uk
Mamoon A
MA
Aldeyab
Mary P
MP
Kearney
Michael G
MG
Scott
Motasem A
MA
Aldiab
Yaser M
YM
Alahmadi
Feras W
FW
Darwish Elhajji
Fidelma A
FA
Magee
James C
JC
McElnay
D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D016360:Clostridioides difficile / Q000302:isolation & purification*; D003015:Clostridium Infections / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D003967:Diarrhea / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D004363:Drug Utilization / Q000592:standards* / Q000706:statistics & numerical data; D006761:Hospitals; D006801:Humans; D015994:Incidence; D012189:Retrospective Studies
D000900:Anti-Bacterial Agents