A new study of US commercial insurance data suggests antibiotic prescribing for acute sinusitis frequently veers from expert recommendations.
The study, published yesterday in Open Forum Infectious Diseases, found that nearly a third of the antibiotic prescriptions for acute sinusitis over a 5-year period were not for guideline-recommended agents. And even when first- and second-line antibiotics were prescribed, the duration of the prescriptions exceeded the recommended length of therapy as much as 75% of the time. People living in rural areas and those treated at urgent care clinics were more likely to receive guideline-discordant therapy.
Acute sinusitis is the most common indication for antibiotics in US outpatient settings, accounting for nearly 3.7 million antibiotic courses a year. But because the prevalence of bacterial sinusitis is low, antibiotics are often unnecessary. The authors of the study say the findings indicate that even when antibiotics for sinusitis are appropriate, prescribing can be improved.
Guideline-discordant agents, durations
Using data from a large US database of commercially insured individuals, a team led by researchers from the Centers for Disease Control and Prevention (CDC) identified adults ages 18 to 64 treated in outpatient settings for a sinusitis diagnosis from 2016 through 2020. The primary outcome was receipt of an antibiotic within 3 days of diagnosis and whether the antibiotic selection was guideline-concordant as defined by Infectious Diseases Society of America guidelines (use of first- and second-line antibiotics for 7 days or less). Encounters with no antibiotic prescription were also included.
The researchers also examined several patient- and prescriber-level factors associated with guideline-discordant antibiotic prescriptions.
Of the 4,689,850 sinusitis encounters included in the study, 82.6% resulted in an antibiotic prescription, with 53.1% resulting in a guideline-concordant antibiotic (42.9% first-line agents and 10.2% second-line agents) and 29.5% resulting in a guideline-discordant antibiotic. The most commonly prescribed antibiotic was amoxicillin-clavulanate (38.5%), which is a first-line agent. The second most-prescribed antibiotic was azithromycin (22%), which is not recommended for sinusitis.
Overall, the median treatment duration was 10 days, with 75% of first-line agents and 63% of second-line agents prescribed for more than 7 days.
Analysis of patient- and prescriber-level factors found that adults living in rural areas were 8% less likely to receive a guideline-concordant agent (adjusted risk ratio [aRR], 0.92; 95% confidence interval [CI], 0.92 to 0.92) and 23% less likely to receive a prescription with a guideline-concordant duration (aRR, 0.77; 95% CI, 0.76 to 0.77) than patients in urban areas.
Urgent care encounters were 24% less likely to result in a prescription with a guideline-concordant duration (aRR, 0.76; 95% CI, 0.75 to 0.76) than office encounters. These findings are consistent with previous studies that have found higher rates of antibiotic prescribing in rural areas and urgent care settings.
The analysis also found that older patients (ages 25 to 44) were more likely to receive guideline-concordant antibiotics (aRR, 1.05; 95% CI, 1.04 to 1.05) than younger patients (18 to 24), while women were less likely than men to receive guideline-concordant antibiotics (aRR, 0.97; 95% CI, 0.97 to 0.98). But the researchers concluded that those associations had a small magnitude of effect.
Optimizing antibiotic prescribing for sinusitis
While the study was not able to assess the clinical criteria used to diagnose bacterial sinusitis and therefore couldn't determine the appropriateness of the antibiotic prescriptions, the authors say the 17.4% of sinusitis encounters that did not result in an antibiotic prescription "likely reflects the overtreatment of adults with antibiotic therapy."
They also note that the majority of those encounters were in the emergency department, which suggests it's possible that strategies to reduce unnecessary prescribing are being implemented in those settings.
"Most cases of acute sinusitis have a viral etiology, and a recent cross-sectional study showed that approximately 50% of encounters for sinusitis do not warrant an antibiotic prescription," they wrote. "In this study, only encounters at an emergency department had such high proportion, with 57% of them not resulting in an antibiotic prescription."
To help reduce overtreatment of sinusitis, the authors say antibiotic stewardship programs should focus on watchful waiting, delayed prescribing, and addressing perceived patient expectations.
"Evidence shows that outpatient antibiotic prescribing can be improved, and patients may still be satisfied without an antibiotic if their communication expectations are met," they wrote.
But they add that the findings also indicate that more can be done to optimize antibiotic prescribing for sinusitis when it's warranted. Prescribing antibiotics for longer than recommended, for example, can result in adverse events like Clostridioides difficile infection, the risk of which has been found to increase with antibiotic duration.
"This risk can be reduced by prescribing guideline-concordant durations, leading to similar outcomes and fewer adverse events compared to longer durations," they wrote. "Therefore, it is important that antibiotic stewardship programs develop interventions aimed at improving overall prescribing for acute sinusitis."
