Two studies conducted in Canada suggest efforts to reduce unnecessary antibiotic prescribing in primary care have had mixed results, with behavior-changing interventions showing more of an impact than education alone.
In a randomized clinical trial published today in JAMA Internal Medicine, a research team led by Public Health Ontario found that sending a letter to primary care physicians (PCPs) informing them that they are in the highest quartile of antibiotic prescribers compared with peers resulted in fewer overall prescriptions, fewer prolonged-duration prescriptions, and reduced drug costs.
Meanwhile, a study published yesterday in the Journal of Antimicrobial Chemotherapy found that Canada's campaign to reduce antibiotic use for respiratory infections (RTIs) through education and awareness did not cause a significant change in short-term prescribing patterns for RTIs.
Peer-comparison letters
The randomized controlled trial involved 3,500 family physicians or general practitioners who were ranked as the highest antibiotic prescribing PCPs in Ontario based on data from March 2017 through February 2018. The PCPs were split into three groups, with 1,500 receiving a letter containing recommendations on antibiotic initiation in early December 2018, 1,500 receiving a letter with recommendations on appropriate antibiotic prescribing durations, and a control group of 500 PCPs who did not receive a letter.
The letters contained recommendations and tools adapted from Choosing Wisely Canada, a national campaign to reduce unnecessary treatments and tests in healthcare, and were co-signed by leading medical officials in the province. The idea behind sending the letters was that showing high-prescribing PCPs that their behavior was out of the norm may spur a change in prescribing, and providing information on appropriate initiation and duration could have an additional impact.
The trial had three prespecified outcomes. The primary outcome was the total number of antibiotic prescriptions in the 12 months after the letters were sent, compared with baseline data collected 12 months prior to the intervention. The other outcomes were the number of prolonged-duration antibiotic prescriptions (defined as more than 7 days) and total antibiotic costs.
At baseline, the PCPs who received the initiation and duration letters averaged 988 and 1,000 antibiotic prescriptions per year, respectively, and the control PCPs averaged 988 prescriptions. At 12 months post-intervention, PCPs who received the initiation letters averaged 849 antibiotic prescriptions per year, the PCPs who received the duration letter averaged 851, and the control PCPs averaged 881.
While there was no statistically significant difference in total antibiotic use between the initiation letter arm and the duration letter arm, the receipt of either letter resulted in a statistically significant 4.2% relative difference in total antibiotic use compared with controls (relative risk [RR], 0.96; 97.5% confidence interval [CI], 0.92 to 1.00). Receipt of the duration letter resulted in a 4.8% relative reduction in total antibiotic use (RR, 0.95; 97.5% CI, 0.91 to 1.00) compared with controls.
The analysis of secondary outcomes showed that at baseline, PCPs who received the duration letter averaged 332 prolonged-duration antibiotic prescriptions per year, compared with 347 for the controls. Post-intervention, there was a statistically significant 8.1% relative difference in prolonged-duration antibiotic prescriptions between the duration letter arm and the control arm (RR, 0.92; 97.5% CI, 0.87 to 0.97), and a 6.1% reduction in drug costs (RR, 0.94; 97.5% CI, 0.89 to 0.99). There was also a significant difference between the duration letter arm and the initiation letter arm in prolonged-duration antibiotic prescriptions (RR, 0.94; 97.5% CI, 0.90 to 0.98).
Compared with the control PCPs, receipt of the duration letter resulted in 42 fewer antibiotic prescriptions, 24 fewer prolonged-duration prescriptions, and $771 in drug costs savings on average per PCP over 12 months. The study authors estimate that if all 3,500 of the highest-prescribing PCPs in Ontario had received the antibiotic duration letter, there would have been 147,000 fewer antibiotic prescriptions at 12 months, 84,000 fewer prolonged-duration prescriptions, and a $2.7 million reduction in drug costs.
"We demonstrated that a single peer-comparison letter on antibiotic prescribing can reduce drug costs and was successfully implemented across an entire health care system," the study authors concluded. "The addition of a resource on appropriate antibiotic durations resulted in substantial reductions in prolonged-duration prescriptions in addition to reduced overall antibiotic use."
Education alone not enough
In the other study, researchers from the University of Toronto set out to determine whether Choosing Wisely Canada's "Using Antibiotics Wisely in Primary Care" campaign has had any impact on prescribing rates for RTIs.
The campaign, which was launched in November 2018 and includes toolkits and recommendations for clinicians to reduce antibiotic prescribing for acute RTIs, focuses on unnecessary antibiotic prescribing for indications like bronchitis, pharyngitis, and acute otitis media (ear ache), as those are some of the major drivers of unnecessary outpatient prescribing.
Using data from the IQVIA Geographic Prescription Monitor database, which accounts for 75% of prescriptions dispensed by community pharmacies in Canada, the researchers conducted a population-based time-series analysis of antibiotic prescriptions dispensed from January 2015 through December 2019.
Overall, the national prescribing rate of RTI-indicated antibiotics increased by 2.1% from 2015 to 2017 and fell by 3.5% from 2017 through 2019, a trend that was generally consistent across all ages and provinces. But no significant reduction in prescribing—whether it was overall numbers, by specific age-group, or by antibiotic class—was observed following the launch of the Using Antibiotics Wisely campaign. Even provinces that said they prioritized the Using Antibiotics Wisely toolkit didn't see significant change in RTI-indicated antibiotic prescription rates post-intervention.
The rate of RTI-indicated antibiotic use was highest among children and adults 65 years and older.
The study authors note they only had 13 months of data to measure the impact of the campaign, and that there may be a more measurable impact over time. But they suggest that the campaign didn't lead to a significant short-term reduction in antibiotics for RTIs because it's designed as a passive intervention focused on knowledge-sharing.
"There are many factors known to affect antibiotic prescribing for acute RTIs, such as patient and caregiver expectations, medicolegal concerns and time constraints," they wrote. "These factors are unlikely to be impacted by passive educational campaigns alone."
The authors conclude that future community antimicrobial stewardship campaigns should consider adding specific actionable components for clinicians and patients beyond education alone.
