Outpatient antibiotic use in British Columbia, Canada: reviewing major trends since 2000.

Background With 90% of all antibiotics in Canada being used in the community setting, tracking outpatient prescribing is integral to mitigate the issue of antimicrobial resistance. In 2005, a provincial programme was launched in British Columbia (BC) to disseminate information regarding the judicious use of antibiotics. These efforts include educational campaigns, updated practitioner guidelines and academic detailing. The impact of provincial stewardship on community prescribing requires ongoing evaluation. Objectives This study examines outpatient prescribing to quantify rates of antibiotic use, evaluate major trends over time and identify new targets for stewardship. Methods A retrospective cohort design using population-level data. Results This study included over 3.5 million unique individuals with a total of 51 367 938 oral antibiotic prescriptions dispensed over a 19 year period (2000-18). Overall antibiotic utilization decreased by 23% over the course of the study period. This trend in the reduction of antibiotic prescription was observed across all major antibiotic classes, apart from the class of other antibacterials, which was mostly related to use of nitrofurantoin. The largest magnitudes of decreased prescribing were observed in the paediatric population. Prescribing across two distinct eras of provincial stewardship reaffirmed preliminary findings of programme efficacy, when compared with pre-stewardship levels of antibiotic use. Conclusions Outpatient prescribing in BC is decreasing overall, and this study confirms an association between provincial stewardship interventions and improvements in antibiotic use. Pronounced declines in paediatric populations are promising, and further research is underway to examine prescribing quality.