New study Examines extended use of antibiotics

Old habits die hard. A new study shows Ontario family doctors late in their careers are more likely to prescribe antibiotics for longer than their newly graduated counterparts, a prescribing practice shown to increase the risk of building drug resistant microbes.

Ontario’s antibiotic prescribing patterns are well-documented — with Sarnia-Lambton, ChathamKent and Windsor-Essex leading the province in prescription rates — but the new study highlights the most-likely culprits for dispensing the drugs longer than necessary. “This variability is not really necessarily being driven by different patient populations or different diagnoses ... but physician habits and the way physicians were trained,” study co-author and Public Health Ontario researcher Kevin Schwartz said. “That’s something we need to target and change moving forward.” Researchers looked at oral antibiotics prescribed by 10,616 family physicians in Ontario between March 1, 2016 and Feb. 28, 2017. The group prescribed a total of 5.6 million antibiotic courses. Study authors classified the physicians by their career stage, defining early career physicians as ones with less than 11 years since they graduated from medical school, mid-career physicians as having 11 to 24 years practising since graduation and late-career doctors with 25 years or more since they finished medical school. Researchers found late-career doctors are significantly more likely to prescribe a prolonged course of antibiotics — longer than eight days — than early-career family physicians.

An average of 38.6 per cent of antibiotic prescriptions written by late-career family doctors were for long courses of the drug, compared to an average of 30.5 per cent for early-career physicians. Prescribing antibiotics for a shorter period of time is a key part of antibiotic stewardship, Schwartz said. Shorter courses of the drugs give bacteria less of an opportunity to develop resistance to it.

A quick round of antibiotics also limits the chance for waste or abuse by patients. “There’s evidence that’s been building over the last decades showing that shorter durations of antibiotics are equivalent to longer courses of therapy with less side effects and less impact on resistance,” Schwartz said.

The antibiotic prescription issue hits home in Southwestern Ontario, where doctors in SarniaLambton, Chatham-Kent and Windsor-Essex lead the province in prescribing rates.

From March 2016 to February 2017, the Erie St. Clair Local Health Integration Network (LHIN) had the highest antibiotic prescribing rate in the province, 778 prescriptions per 1,000 people each year. Though patient expectations and demographic characteristics, including socioeconomic status and rural or urban clinic settings, can play a role in how doctors dole out the drugs, Schwartz said doctors own habits play a role, too. Schwartz wants to see more focus on antibiotic stewardship among the older generation of doctors, who may not be as versed as their younger colleagues on the optimal way to dispense the drugs. “Medical education was probably very different back then about antibiotic prescribing and the risks of over-prescribing an antibiotic weren’t well appreciated,” he said. But it’s not all doom and gloom, he said.

“On the other side, this gives us some hope for the future. We know that the younger doctors are doing this more appropriately,” Schwartz said.

“There’s more of a focus on using antibiotics more judiciously. It shows that we’re doing at least some things right.”

The study appears in the latest edition of the Oxford University Press academic journal Clinical Infectious Diseases.