Antibiotic Use Varies Across Canada's Provinces

Carolyn Crist

April 12, 2022

Antibiotic use varies significantly across Canadian provinces, highlighting the need for provincial targets to reduce antibiotic overuse and antimicrobial resistance, according to new data.

Overall antibiotic dispensing rates in Newfoundland, Labrador, and Saskatchewan significantly exceeded the national rate, the researchers found, whereas the rate in British Columbia was significantly below the national average.

"British Columbia has been a leader nationally and internationally in monitoring and interventions," senior author Mina Tadrous, PharmD, PhD, an assistant professor at the University of Toronto's Leslie Dan Faculty of Pharmacy, Ontario, Canada, told Medscape Medical News.

"What their work highlights is that it takes time and multiple interventions to tackle the problem," he said. "Lower rates are a culmination of time, an iterative approach, and evidence-based initiatives to tackle overuse in a substantial way."

The findings were published online March 22 in CMAJ Open.

Decline in Dispensing Rate

Tadrous and colleagues conducted a cross-sectional analysis of antibiotic prescriptions dispensed in Canadian provinces in 2019 using the IQVIA Geographic Prescription Monitor database. They looked at annual rates of overall antibiotic dispensing, broad-spectrum antibiotic dispensing, and age-specific antibiotic dispensing as prescriptions per 1000 population in each province and nationally.

The research team found that a total of 23,406,640 antibiotic prescriptions were dispensed nationally in 2019, at a rate of about 627 prescriptions per 1000 people. Overall antibiotic dispensing rates in Newfoundland and Labrador were 920.5 prescriptions per 1000 population, followed by nearly 714 prescriptions per 1000 population in Saskatchewan. In British Columbia, the rate was approximately 543 prescriptions per 1000 population.

Age-adjusted dispensing rates ranged from 531.5 prescriptions per 1000 population in British Columbia to about 909 prescriptions per 1000 population in Newfoundland and Labrador. The national rate of antibiotic dispensing for children was about 550 prescriptions per 1000 population, the rate for adults was 557 prescriptions per 1000 population, and the rate for older adults was about 939 prescriptions per 1000 population. Newfoundland and Labrador had the highest rates of antibiotic dispensing for all age groups, and British Columbia had the lowest rates of antibiotic dispensing for all age groups.

The five most commonly prescribed antibiotic classes nationally were narrow-spectrum penicillins (28.6%), macrolides (14%), first-generation cephalosporins (9.1%), tetracyclines (7.6%), and penicillins with beta-lactamase inhibitors (7.6%).

Overall, the observed national annual dispensing rate was 5.8% lower than the rate observed in 2009, the researchers write, despite an increase in the average age of the Canadian population. The Canadian rate is below the dispensing rate observed in the United States (791 per 1000 population) but higher than European prescribing rates (563 per 1000 population in England, 450 per 1000 population in Norway, and 285 per 1000 population in Sweden).

International and interprovincial variation in prescribing rates can be attributed partly to various stewardship initiatives in Canada, the researchers write. In British Columbia, provincially funded stewardship programs have been in place since 2005 and have led to a "substantial reduction" in antibiotic use, they say.

"Reducing the overuse of antibiotics, with the specific concern of antimicrobial resistance growing, has been a goal globally," said Tadrous. "That's why it's important to continue to drive down the gap between what's appropriate use and what's not."

Refining Antibiotic Targets  

In a 2019 report, the Public Health Agency of Canada called for detailed research on antibiotic use to explain interprovincial variation and develop appropriate Canadian targets for antibiotic use. In this study, Tadrous and colleagues found that targets could be developed for specific high-risk drug classes.

In Quebec, for instance, the overall dispensing rate was similar to the national rate, but the provincial rate of fluoroquinolone was significantly higher. In Prince Edward Island, the fluoroquinolone dispensing rate was the lowest in Canada, the researchers write, but still higher than the target in other countries such as Belgium.

Because medical needs vary by population, patient factors and interphysician variability should be considered as well, the researchers write. Interventions for high-prescribing physicians, for instance, can play an important role in community antimicrobial stewardship programs. In one intervention, sending letters to physicians that compared their prescribing rates to those of other doctors led to an improvement, Tadrous said.

"The idea is not just to measure and point out problems but to develop solutions," he said.

"A Slower-Moving Pandemic"

One of the best ways to improve stewardship is to ensure healthcare providers have access to the most current selection of treatment options, Lori Burrows, PhD, professor of biochemistry and biomedical sciences at McMaster University in Hamilton, Ontario, Canada, told Medscape Medical News. Burrows, who wasn't involved with this study, has conducted research with the Canadian Antimicrobial Innovation Coalition.

Many Canadian physicians don't have easy access to newer antibiotics and often resort to prescribing older, generic treatments that may be ineffective because of antimicrobial resistance, she said. Newer drugs have been approved for use in other countries but not in Canada. This discrepancy results from factors such as the cost of developing the drugs, stewardship principles that reduce the return on investment for drug companies, and other financial barriers in the Canadian market due to the country's small population and regulatory processes.

"Because of our stewardship programs, we need to start thinking about different ways to pay for antibiotics," said Burrows. "If the federal government gives the money to the provinces, then it's up to them to decide whether to bother paying for new antibiotics."

The COVID-19 pandemic provided a preview of what uncontrolled drug resistance might look like, with an infectious disease that had no viable treatment options, she said. However, the pandemic response also showed how federal and provincial governments could work together to address a serious public health threat.

"While antimicrobial resistance is a slower-moving pandemic than COVID-19, it will have massive impact on complex medical procedures we now take for granted," she said. "More urgency is needed in our efforts to bring new antibiotic options to Canada to slow the development of resistance, to save lives, and to reduce pressure on our healthcare system."

The study was funded by the Ontario Ministry of Health. Tadrous and Burrows have reported no relevant disclosures.

CMAJ. Published online March 22, 2022. Full text

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