AOM is one of the most common infections in early infancy and childhood, causing pain and general symptoms of illness such as fever, irritability and problems feeding and sleeping. By three years of age, most children have had at least one AOM episode. Though AOM usually resolves without treatment, it is often treated with antibiotics.
The evidence in this review is current to 26 April 2015.
For the review of antibiotics against placebo we included 13 trials (3401 children aged between two months and 15 years) from high-income countries with generally low risk of bias. Three trials were performed in a general practice (GP) setting, six in an outpatient hospital setting and four in both settings.
For the review of antibiotics against expectant observation, five trials (1149 children) from high-income countries were eligible with low to moderate risk of bias. Two trials were performed in a GP setting and three in an outpatient hospital setting. Four trials (1007 children) reported outcome data that could be used for this review.
We found that antibiotics were not very useful for most children with AOM; antibiotics did not decrease the number of children with pain at 24 hours (when 60% of children were better anyway), only slightly reduced the number of children with pain in the days following and did not reduce the number of children with late AOM recurrences and hearing loss (that can last several weeks) at three months compared with placebo. However, antibiotics did slightly reduce the number of children with perforations of the eardrum and AOM episodes in the initially unaffected ear compared with placebo. Results from an individual patient data meta-analysis including data from six high-quality trials (1643 children), which were also included as individual trials in our review, showed that antibiotics seem to be most beneficial in children younger than two years of age with infection in both ears and in children with both AOM and a discharging ear.
We found no difference between immediate antibiotics and expectant observational approaches in the number of children with pain three to seven days and 11 to 14 days after assessment. Furthermore, no differences in the number of children with hearing loss at four weeks, perforations of the eardrum and late AOM recurrences were observed between groups.
There was not enough information to know if antibiotics reduced rare complications such as mastoiditis (infection of the bones around the ear). All of the studies included in this review were from high-income countries. Data are lacking from populations in which the AOM incidence and risk of progression to mastoiditis is higher.
Antibiotics caused unwanted effects such as diarrhoea, vomiting and rash and may also increase resistance to antibiotics in the community. It is difficult to balance the small benefits against the small harms of antibiotics in children with AOM. However, for most children with mild disease in high-income countries, an expectant observational approach seems justified.
Quality of the evidence
We judged the quality of the evidence to be high for most of the outcomes in the review of antibiotics against placebo (this means that further research is very unlikely to change our confidence in the estimate of effect).
For the review of immediate antibiotics versus expectant observation, we judged the evidence to be of moderate quality for most of the outcomes (this means that further research is likely to have an important impact on how confident we are in the results and may change those results). Quality was affected by concerns about sample size (perforation of the eardrum, rare complications) and the large number of children who are 'lost to follow-up' (pain at days 11 to 14, hearing loss at four weeks and late AOM recurrences).
Authors' conclusions:
This review reveals that antibiotics have no early effect on pain, a slight effect on pain in the days following and only a modest effect on the number of children with tympanic perforations, contralateral otitis episodes and abnormal tympanometry findings at two to four weeks and at six to eight weeks compared with placebo in children with AOM. In high-income countries, most cases of AOM spontaneously remit without complications. The benefits of antibiotics must be weighed against the possible harms: for every 14 children treated with antibiotics one child experienced an adverse event (such as vomiting, diarrhoea or rash) that would not have occurred if antibiotics were withheld. Therefore clinical management should emphasise advice about adequate analgesia and the limited role for antibiotics. Antibiotics are most useful in children under two years of age with bilateral AOM, or with both AOM and otorrhoea. For most other children with mild disease in high-income countries, an expectant observational approach seems justified.