Antibiotic resistance, where infection-causing bacteria no longer respond to common drugs meant to kill them, is a huge and emerging issue in public health.
And one of the biggest contributors to the problem is doctors.
“The single biggest driver of that resistance is the amount of antibiotics that we use,” said Dr. Kevin Schwartz, a physician who works in antimicrobial stewardship and infection prevention and control with Public Health Ontario.
According to data from the Public Health Agency of Canada, most antibiotics in Canada are used in the community, not the hospital, meaning they’re being prescribed by ordinary physicians or dentists. Family physicians account for 65 per cent of prescriptions.
Not everyone prescribes at the same rate either. On average, there are about 625 antibiotic prescriptions per 1,000 inhabitants in Canada. In B.C., there are 546.
In Newfoundland and Labrador, the highest-prescribing province, there were 956 prescriptions for every 1,000 people.
The differences go even further: according to preliminary research from Public Health Ontario, the southwestern Ontario health region of Erie-St-Clair has an antibiotic rate one-and-a-half times higher than the lowest health region. Mississauga has the second-highest prescribing rate.
Antibiotic prescribing matters for our ability to treat infections in the future, as our current slate of antibiotic drugs will gradually become less and less effective.
Not only that, said Schwartz, but many of the biggest advances in modern medicine: things like cancer care, organ transplants and care of premature babies, are only possible because of antibiotics.
“The most common reason why those procedures don’t work and never worked historically were because patients would develop complications and those can be fatal. And the most common one would be an infection.”
WATCH: Public Health Ontario says the individual citizen and the medical community are both responsible for fighting antibiotic resistance.
Why physicians prescribe
There are many reasons why one physician might prescribe more antibiotics than another, said Schwartz.
Some have to do with the patient: their age, how sick they are, if the patient expects to be given an antibiotic.
Others have to do with the doctor: how many patients they see in a day, for example. Busier doctors tend to prescribe more antibiotics.
Prescriptions can also vary with the time of year – December versus July – or whether the patient visits a walk-in clinic or sees their regular family doctor.
However, none of these really account for all of the differences between physicians, said Schwartz. “The theory and the likely explanation for that is it’s physician habit. It’s the way that this doctor has always prescribed.”
Some of those prescriptions might not be necessary, such as prescribing an antibiotic to treat an infection caused by a virus, he said, something that one study showed was happening with about half of Ontario seniors who had a viral infection.
Doctors might not be aware that they’re prescribing too often, he said. On a case-by-case basis, everything might look fine.
“If you’ve prescribed antibiotics for a child with a viral infection for 30 years, that child gets better every time you prescribe an antibiotic because they would have gotten better anyways.”
Schwartz isn’t sure yet why physicians in Erie-St-Clair and Mississauga prescribe so many antibiotics though Public Health Ontario is researching the question. It doesn’t seem to be related to income, or rural vs. urban centres, or other such demographic factors.
Again, he thinks it’s about physicians’ habits. “So there are certain physicians who have historically prescribed a lot of antibiotics and there’s probably not equal distribution of those physicians across the province.”
WATCH: Antibiotic-resistant bacteria are on the rise and spreading worldwide. New testing in the U.S. has found an increasing number of “nightmare bacteria” across the country, but tracking these potentially deadly superbugs is much more difficult here in Canada.
Ontario Public Health is also looking at ways to change those habits.
Programs in the U.K. and Australia sent letters to high-prescribing physicians, letting them know that they prescribe more antibiotics than their peers. And those projects appear to have worked. In Australia, six months after the letters were sent, those physicians reduced their prescriptions by between nine and 12 per cent, says their government.
Ontario is contemplating a similar approach, with a study perhaps beginning this flu season to examine the effectiveness of different kinds of messages.
They’re also trying to figure out what exactly the optimal prescribing level might be.
“We know that we probably need to reduce antibiotic use, but what we don’t have a clear answer for in Ontario is by how much,” said Schwartz.
“Obviously antibiotics are critical, life-saving, important medications and we want patients to be getting them appropriately. But what we don’t want is people with viral illnesses that are going to get better anyway to be getting antibiotics. We also certainly don’t want people who need the antibiotics to not be getting them.”