Antimicrobial stewardship in companion animal practice: an implementation trial in 135 general practice veterinary clinics

Abstract

Background: Antimicrobial stewardship programmes (ASPs) have been widely implemented in medical practice to improve antimicrobial prescribing and reduce selection for multidrug-resistant pathogens.

Objectives: To implement different antimicrobial stewardship intervention packages in 135 veterinary practices and assess their impact on antimicrobial prescribing.

Methods: In October 2018, general veterinary clinics were assigned to one of three levels of ASP, education only (CON), intermediate (AMS1) or intensive (AMS2). De-identified prescribing data (1 October 2016 to 31 October 2020), sourced from VetCompass Australia, were analysed and a Poisson regression model fitted to identify the effect of the interventions on the incidence rates of antimicrobial prescribing.

Results: The overall incidence rate (IR) of antimicrobial prescribing for dogs and cats prior to the intervention was 3.7/100 consultations, which declined by 36% (2.4/100) in the implementation period, and by 50% (1.9/100) during the post-implementation period. Compared with CON, in AMS2 there was a 4% and 6% reduction in the overall IR of antimicrobial prescribing, and a 24% and 24% reduction in IR of high importance antimicrobial prescribing, attributable to the intervention in the implementation and post-implementation periods, respectively. A greater mean difference in the IR of antimicrobial prescribing was seen in high-prescribing clinics.

Conclusions: These AMS interventions had a positive impact in a large group of general veterinary practices, resulting in a decline in overall antimicrobial use and a shift towards use of antimicrobials rated as low importance, with the greatest impact in high-prescribing clinics.

Figure 1.

Flow diagram of clinic recruitment and allocation. CON, education only intervention; AMS1, intermediate intervention; AMS2, intensive intervention.

Figure 2.

Interventions included in each arm of the antimicrobial stewardship trial in general practice veterinary clinics. CON, education only intervention; AMS1, intermediate intervention; AMS2, intensive intervention. The CON programme (n = 44) included only the first level of interventions (a), the AMS1 programme (n = 47) included all interventions from the first two levels (a and b) and the AMS2 programme (n = 44) included all the interventions (a, b and c).

Figure 3.

Categorization of antimicrobials for the traffic light colour-coding system implemented in AMS1 and AMS2.

Figure 4.

Unadjusted incidence rate (per 100 consultations) of antimicrobial prescribing in CON (yellow), AMS1 (purple) and AMS2 (blue) for (a) low-, (b) medium- and (c) high-rated antimicrobials according to the Australian Scientific and Technical Advisory Group on AMR in the pre-trial and trial periods (1/1/2016 to 31/10/2020). CON, education only intervention; AMS1, intermediate intervention; AMS2, intensive intervention.