The most important caveat is that all trials included in the Cochrane review were conducted in high-income countries. Thus, the results might not be generalizable to lower-income countries. In populations with a higher risk of mastoiditis or with lower immunization coverage, antibiotics might prevent serious complications.
Another notable caveat is the inclusion of patients who received delayed antibiotics in the expectant observation group. In some trials, patients assigned to the observation group were given a prescription but were instructed to withhold antibiotics for 72 hours and to initiate treatment only if symptoms persisted. Delayed antibiotic use might have affected the benefit or harm outcomes in such trials.
Not all trials had specific protocols for pain management (e.g., ibuprofen, acetaminophen). Given that pain reduction was the primary outcome in most trials, the presence or absence of a pain control protocol or of clear instructions for the parents could have influenced the outcomes.
A review of the literature indicates that physicians overdiagnose otitis media, which may result in underestimation of a treatment effect. A rational clinical examination sys- tematic review showed that on pneumatic otoscopy, cloudy (adjusted likelihood ratio [LR] = 34; 95% CI, 28 to 42), bulging (adjusted LR = 51; 95% CI, 36 to 73), and distinctly immobile (adjusted LR = 31; 95% CI, 26 to 37) tympanic membranes were the most useful signs of otitis media.
The methodologic quality of the studies included in the review was deemed to be high, and the evidence for most of the outcomes was considered to be of high quality. For the outcomes of pain at 10 to 12 days, long-term effects, and serious complications, the evidence from the included studies was judged to be of moderate quality because of reporting bias, low sample size, and potential attrition bias.
Factors such as patients being recruited from different practice settings might have contributed to some heterogeneity among the trials. In addition, the duration of antibiotic therapy varied from seven to 14 days in the included trials. Most of the primary outcomes were measured within the first seven days of antibiotic therapy, but a longer duration of antibiotic therapy may have affected secondary outcomes.
The original manuscript was published in
Medicine by the Numbers, American Family Physician as part of the partnership between TheNNT.com and AFP.
See theNNT.com's previous reviews of this topic:
Antibiotics for Acute Otitis Media, January 22, 2015
Antibiotics for Acute Otitis Media, August 22, 2010