Young and colleagues1
aggregated and analyzed individual patient-level data from all known placebo-controlled, randomized, antibiotic treatment trials of adults with clinical symptoms of acute sinusitis that were conducted in primary care settings. They excluded trials that used imaging or bacterial culture as part of patient recruitment.
Studies were included that allowed the use of concomitant medication such as nonsteroidal anti-inflammatory drugs, decongestants, or nasal steroids, as long as patients in both groups had access to the same medications. All trials excluded patients with severe symptoms such as high fever, periorbital swelling or erythema, or intense facial pain, important exclusions that we will discuss below.
The current recommendation to use antibiotics if illness lasts more than 1 week was based on expert opinion, not clinical trials
They identified 10 such studies and completed an intent-to-treat analysis of the 9 double-blind trials for which patient level data were available. Using individual data from 2547 patients, the odds ratio for an overall antibiotic treatment effect was 1.37 (95% confidence interval, 1.13-1.66), with a number needed to treat (NNT) of 15.
This finding means that 15 patients needed to be given an antibiotic for 1 additional patient to be cured at 8 to 15 days after treatment commenced. Using statistical modeling, they determined that 64% of patients treated with placebo were cured at 14 days compared with 70% given an antibiotic. One patient out of 1381 treated with placebo experienced a serious complication, a brain abscess.
Do antibiotics benefit any subgroups?
The investigators also analyzed the prognostic value of specific signs and symptoms to answer the question: Is there any subgroup of patients who might benefit more from antibiotic treatment?
Duration. Patients with a longer duration of symptoms, more severe symptoms, or increased age took longer to cure, but were no more likely to benefit from antibiotic treatment than other patients.
Symptoms, such as a previous common cold, pain on bending, unilateral facial pain, tooth pain, and purulent nasal discharge did not have any prognostic value.
Only one sign
—purulent discharge noted in the pharynx on examination—was associated with a higher likelihood of benefit from treatment with antibiotics, but the NNT was still 8 in this group. Patients with symptoms for 7 days or longer were no more likely to respond to antibiotics than those with symptoms for fewer than 7 days.1