Time Series Analysis of the Impact of an Intervention in Tayside, Scotland to Reduce Primary Care Broad-Spectrum Antimicrobial Use
Hernandez-Santiago V, Marwick CA, Patton A, Davey PG, Donnan PT, Guthrie B
J Antimicrob Chemother. 2015 May 7. [Epub ahead of print]
Targeting High-Risk Antibiotics
A study by Hernandez-Santiago and colleagues demonstrates the impact of a population-wide intervention in reducing high-risk antibiotic use. Investigators assessed the impact of a multicomponent intervention implemented in Tayside, Scotland on reducing prescribing rates of the "4C antimicrobials"—co-amoxiclav, ciprofloxacin, cephalosporins, and clindamycin. Specifically, this intervention was designed to target primary care prescribing of antibiotics considered high risk for their association with Clostridium difficile infection. Components of the intervention included distribution of educational material, feedback to practices on antibiotic use and setting antibiotic reduction targets, and advisory discussions with local antibiotic stewardship teams.
Results of interrupted time series analyses using 8 years of prescribing data showed a slightly downward trend for 4C prescribing during the preintervention period. However, in the postintervention period, at 12 months, 4C antibiotic prescribing was 42.2% lower; at 24 months, prescribing was 55.5% lower. The most significant reduction occurred in the care of individuals aged 65 years and older and care home residents. There were increases in the use of doxycycline, trimethoprim, and nitrofurantoin but no significant change in the trend of overall antibiotic prescribing in the postintervention period.
Viewpoint
The results of this study demonstrate the substantial impact of a multicomponent intervention in reducing high-risk antibiotic use in the primary care setting, which likely contributed to the major reduction in C difficile infection seen in the region over the same time period. However, there was no reduction in overall antibiotic prescribing, probably owing to increases in the use of "substitute" antibiotics. Nevertheless, this study highlights the importance of stewardship interventions in the outpatient setting in reducing antibiotic resistance and overall rates of C difficile infection.