A new study by researchers in Canada suggests that an effort to reduce antibiotic prescribing in one age-group had spillover effects on a broader population.
The study, published last week in JAMA Network Open, was a secondary analysis of a randomized controlled trial conducted among family physicians in Ontario who prescribed antibiotics for patients aged 65 and older. In that trial, investigators observed a 5% relative reduction in antibiotic prescribing and 14% relative reduction prolonged duration prescribing among physicians who received a peer comparison feedback letter. But the data used for that trial were limited to antibiotic prescriptions for older patients.
To see if the intervention had a similar impact on a broader patient population, a team led by researchers from Public Health Ontario and the University of Toronto reevaluated it using a different administrative data source. They found that the audit-and-feedback letters resulted in reductions in antibiotic prescribing and prolonged duration prescribing across all patient ages.
“Our study found that audit-and-feedback interventions using administrative data for older patients was associated with a broader shift in prescribing behavior, promoting judicious antibiotic use across all age groups,” the study authors wrote.
Consistent reductions across age and sex groups
In the original trial, conducted from January 2021 through December 2022 and published last year, enrolled family physicians in Ontario were randomly assigned 4:1 to receive a peer comparison antibiotic prescribing feedback letter or no correspondence. The letter provided recipients with the percentage of their peers who were prescribing fewer antibiotics than them and included information on patient harms, recommended antibiotic durations, and evidence-based communication tips.
The original trial used the Ontario Drug Benefit database, which contains prescription data only for patients aged 65 and older, for the feedback letters and to assess the impact of the intervention. For the post hoc analysis, the researchers linked the randomization group and the trial data set to the IQVIA Xponent antibiotic database for all patients ages. The primary outcome was the total number of antibiotic prescriptions by physicians 12 months after the intervention.
Overall, 4,964 family physicians were included in the study, with 3,967 (74.5%) in the intervention group and 2,549 (25.5%) in the control group. More than half of the physicians in the study (55.7%) were men, and 51.3% had been in practice for 25 years or more.
Our study found that audit-and-feedback interventions using administrative data for older patients was associated with a broader shift in prescribing behavior, promoting judicious antibiotic use across all age groups.
At 12 months after the intervention, the physicians who received audit-and-feedback letters showed a 7% relative reduction in antibiotic prescribing compared with the control group (adjusted rate ratio [aRR], 0.93; 95% confidence interval [CI], 0.93 to 0.94). When broken down by patient age and sex groups, the intervention was still associated with reduced prescribing in patients 65 and older but also in several other groups, including female patients younger than 18 years (aRR, 0.91; 95% CI, 0.89 to 0.93), male patients aged 18 to 64 years (aRR, 0.92; 95% CI, 0.91 to 0.92), and female patients aged 18 to 64 years (aRR, 0.95; 95% CI, 0.95 to 0.96).
“The effect sizes were consistent across various age and sex groups, underscoring the intervention’s outcomes for older adults and spillover to the broader population, including younger age groups,” the authors wrote.
The analysis also showed an 18% relative decrease across all age-groups in the number of antibiotic prescriptions exceeding 7 days duration among physicians in the intervention group (aRR, 0.82; 95% CI, 0.82 to 0.83).
‘Universal relevance’ of judicious antibiotic use
The authors say the spillover effect can be explained in part by the “universal relevance” of the messaging and education provided in the feedback letters.
“Although the feedback might be derived from data specific to a subgroup, such as patients aged 65 years and older, the principles for responsible antibiotic use are applicable across all age groups,” they wrote. “This broad applicability ensures that the data resonates with physicians’ overall practice patterns, rather than being limited to a specific patient demographic.”
They add that the findings underscore the potential of peer comparison audit and feedback, even when targeted at a specific group, to improve overall care quality, reduce antibiotic-related adverse events, and prevent the development of resistance.
“By fostering more judicious prescribing practices among family physicians, peer comparison audit-and-feedback interventions could enhance patient care quality and support public health objectives,” they concluded.
