214 - Antibiotic Use for Common Infections in British Columbia: A Review of Outpatient Prescribing from 2000 - 2018.

Background: Antimicrobial resistance continues to jeopardize the future of modern medicine; as 92% of all antibiotics are used in the community, it is imperative to parse outpatient prescribing. In British Columbia (BC), efforts to curb the use of these essential medications have included: stewardship campaigns, practitioner guidelines, and vaccine scheduling amendments. This study reviews the trends in antibiotic use over the past two decades to identify new targets for Provincial stewardship and intervention.

Methods: Antibiotic prescription information was extracted from PharmaNet, a centralized data system that links all pharmacies with prescriptions dispensed in the community setting. The Medical Service Plan records reimbursement claims submitted by physicians for services provided, including diagnostic codes. Antibiotic prescriptions were extracted from PharmaNet and then matched to the billing system using anonymized patient identifiers. Prescription rates were calculated, and trends were examined by major anatomical therapeutic chemical (ATC) classification.

Results: Our study included 3,564,258 individuals over an 18-year period, with a total of 26,108,576 antibiotic prescriptions issued, for common infections.  Overall antibiotic utilization decreased 18% (from 228 to 187 prescriptions per 1000 population) over the course of the study period. This trend was reflected in both Beta-Lactam (-37%) and Macrolide (-50%) antibiotics; two of the most common classes prescribed in the outpatient setting. A significant outlier was the J01X class of Other Antibacterials, which increased by a staggering 218%, by 2018. Further analyses are currently underway to stratify these changes in magnitude by demographic variables to identify specific, new targets for stewardship.Rates of outpatient antibiotic prescriptions, for common infections, per 1000 population, by major ATC class, over time.


Conclusion: Outpatient antibiotic prescribing has decreased steadily since 2000. These promising results can be ascribed to the various Provincial initiatives to quell the misuse of these medications. However, many of the indications tied to these prescriptions do not warrant the use of antibiotics, and further analyses are necessary to evaluate prescribing quality to fully delineate the state of antibiotic use in BC. Next steps also include comparing BC rates with Ontario, another large province of Canada.