Medicare study puts spotlight on high-volume antibiotic prescribers

Doctor prescribing medicine
Doctor prescribing medicine

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A review of data on outpatient prescriptions for Medicare patients shows that high-volume antibiotic prescribers are responsible for a disproportionate number of antibiotic prescriptions in this group, researchers reported today in Morbidity and Mortality Weekly Reports.

The study, led by researchers with the Centers for Disease Control and Prevention (CDC) Division of Healthcare Quality Promotion, found that, among more than 59 million antibiotic prescriptions written for Medicare Part D beneficiaries in 2019, 41% came from the top 10% of prescribers, who prescribed antibiotics at a rate 60% higher than that of lower-volume prescribers. Nearly half of those prescribers were located in southern states.

Medicare Part D provides prescription drug benefits for roughly 70% of Medicare patients.

The study authors say the findings could present an opportunity for more focused, targeted antibiotic stewardship efforts.

Targeting high-volume prescribers

Using a publicly available Medicare Part D data set that contains prescriber-level aggregate counts of outpatient prescriptions for three types of medication (antibiotics, antipsychotics, and opioids), the researchers assessed antibiotic prescriptions among US healthcare providers who distributed 11 or more antibiotic prescriptions in 2019, comparing high-volume prescribers with lower-volume prescribers.

High-volume prescribers were defined as those in the highest 10th percentile of prescriber-level antibiotic volume across all Medicare providers. To verify that the amount of antibiotics prescribed was not driven exclusively by the number of Medicare Part D beneficiaries seen by a provider, the researchers calculated the percentage of beneficiaries with an antibiotic prescription and the prescriber's antibiotic volume per 100,000 beneficiaries.

Medicare Part D beneficiaries filled 59.4 million antibiotic prescriptions in 2019, with a median of 47 prescriptions per prescriber. Of those, 24.4 million (41%) were written by 69,835 providers in the top 10% of antibiotic prescribers by antibiotic volume.

These high-volume prescribers wrote a median of 284 prescriptions, compared with a median of 41 among lower-volume prescribers. Their median antibiotic prescribing rate was 680 prescriptions per 1,000 beneficiaries, compared with 426 prescriptions/1,000 beneficiaries among low-volume prescribers.

Forty-eight percent of the higher-volume prescribers practiced in the South and prescribed 49% of the total antibiotic prescriptions in this region. They also had the highest median antibiotic prescribing rate (696 prescriptions/1,000 beneficiaries) compared with high-volume prescribers in other regions of the country.

The most common specialties of high-volume prescribers were family practice (21%) and internal medicine (20%).

"This substantial difference in prescribing practices presents opportunities for improved prescribing through antibiotic stewardship activities focusing on these higher-volume prescribers, independent of specialty," the study authors wrote. "Prioritizing higher-volume prescribers for focused stewardship interventions has the potential to have a sizeable impact on antibiotic prescribing, even when data on visit volume, prescribing indications, and appropriateness are not available."

The authors suggest that public health organizations and healthcare systems could start using the publicly available data to identify high-volume prescribers for stewardship outreach, a strategy they suggest could facilitate larger reductions in antibiotic prescribing than targeting lower-volume prescribers. For example, high-volume prescribers could be selected to receive feedback letters with data showing how their prescribing rate compares to peers—an intervention that has been shown to be effective in reducing outpatient prescribing.

"This report demonstrates how publicly available data might be leveraged to monitor antibiotic use and identify higher-volume prescribers," the authors wrote.

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