How many studies does it take to prove a lack of clinical benefit? There have been multiple randomized, controlled trials of antibiotics for acute, uncomplicated sinusitis, and meta-analyses have generally shown only a marginal benefit. That's because the majority of sinusitis cases resolve spontaneously, given enough time.
So what's different about the latest RCT published in this issue of JAMA? The authors of this study decided to test the CDC's conservative recommendations for antibiotic treatment, enrolling only patients who had moderate to severe symptoms present for at least a week. (You could also be enrolled if your symptoms worsened within less than a week.) Physicians diagnosed patients using clinical, rather than imaging, criteria, which closely mirrors what is done in the community. Participants were randomized to either 10 days of amoxicillin or placebo. A narrow-spectrum antibiotic was chosen, again in line with the CDC's recs, and at the time the study was performed, S. pneumoniae antibiotic resistance was rare.
The primary outcome was improvement in rhinosinusitis symptoms by day 3, as measured by the SNOT-16 scale. (Hey, amoxicillin is a generic. You're not going to find any sexy acronyms in this paper.) The scale looked at 16 symptoms, rating them from 0 (none) to 3 (severe). Both groups were allowed symptomatic treatment with pain relievers and decongestants.
One-hundred and sixty-six adults were enrolled. The mean score on the SNOT-16 scale decreased from 1.7 to 1.1 in both groups by day 3. There was also no difference in outcomes by day 10, with both groups dropping to 0.5. There was a statistically significant decrease in symptoms in the amoxicillin group on day 7, but not a clinically significant one: the absolute difference in the symptom score was only 0.2.
Sinusitis accounts for 1 out of 5 antibiotic prescriptions in the U.S. This well-designed trial confirms that they have but a borderline benefit, even in those with prolonged, moderate to severe symptoms. Will primary care doctors finally listen to the results of this latest study?
More importantly, will our patients?