Ontario sees high antibiotic use, raising concerns about resistance

News Release

31 Oct 2018

New research from Public Health Ontario (PHO) has found substantial variability in how often antibiotics are prescribed in Ontario, with some regions seeing prescription rates as high as 778 prescriptions for every 1,000 residents.

Health organizations around the world have called antibiotic resistance an urgent public health issue and one of the greatest threats to global health and food security. To address this issue, greater awareness has focused on antimicrobial stewardship programs, including appropriate prescribing practices, to limit the growth of antibiotic-resistant organisms and their long-term negative impact.

The new study, published in CMAJ Open, examined the frequency with which antibiotics were dispensed to outpatients across 14 health regions in Ontario from March 2016 to February 2017. In that time, more than 8.3 million antibiotic prescriptions were distributed, averaging 621 prescriptions for every 1,000 Ontario residents. For all classes of antibiotics, the highest use region in Ontario saw 778 antibiotic prescriptions filled for every 1,000 residents while the lowest use region saw 534 prescriptions per 1,000 residents.

“From a public health perspective, this is a concern. In the highest use region in Ontario, the data shows that an average of 78 per cent of its residents were prescribed a course of antibiotics during the study year,” says Dr. Kevin Schwartz, infectious disease physician at Public Health Ontario and lead author of the paper. “The research team suspected there was some variability in how often antibiotics were prescribed outside of hospitals and other healthcare institutions, but the level of prescribing was surprising given how much we now know about appropriate prescribing, antibiotic resistance and the long-term dangers of excess prescribing.”

Also surprising were the variations in antibiotic use by age and sex of patients. For women aged 65 and older, the data showed an average of 985 antibiotic prescriptions for every 1,000 women of this age and sex, compared to men aged 18-64 who averaged 441 antibiotics per 1,000. For children under 18, the data revealed a prescription rate of 523 per 1,000; about 80 per cent of these antibiotics were ones most commonly used for respiratory infections.

Dr. Schwartz conducted the research with colleagues in PHO’s Infection Prevention and Control department. They note there are a number of factors that could contribute to this variability in antibiotic use, including the complexity of a patient’s illness, patient expectations, socioeconomic status, physician access, as well as patient and physician knowledge. However, even after adjusting for many of these factors, substantial variability could still be seen.

“Prescriber habit may explain some of this variability. There may be a tendency for more inappropriate prescribing by health care providers in some regions compared to others,” says Dr. Schwartz. “This research highlights the need for ongoing monitoring of antibiotic use as well as greater education and awareness about appropriate prescribing practices.”


Public Health Ontario is a Crown corporation dedicated to protecting and promoting the health of all Ontarians and reducing inequities in health. Public Health Ontario links public health practitioners, front-line health workers and researchers to the best scientific intelligence and knowledge from around the world. For the latest PHO news, follow us on Twitter: @publichealthON.

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Updated 31 Oct 2018