Antibiotic use and serious complications following acute otitis media and acute sinusitis: a retrospective cohort study

Background Most people with acute otitis media (AOM) and acute sinusitis (AS) do not benefit from antibiotics, and GPs are under increasing pressure to reduce antibiotic prescribing. Concern about the risk of complications can drive unnecessary prescribing. Aim To describe the incidence of serious complications following AOM and AS, and to determine whether antibiotics are protective. Design and setting This was a retrospective cohort study using the Clinical Practice Research Datalink database to identify patients diagnosed in general practice with AOM or AS between 1 January 1982 and 31 December 2012. Method The incidence of brain abscess and acute mastoiditis following AOM, and of brain abscess and orbital cellulitis following AS, were calculated, as was the association between antibiotics and the development of these complications and numbers needed to treat (NNT). Results The incidence of brain abscess and acute mastoiditis following AOM were 0.03 (95% confidence interval [CI] = 0.01 to 0.20) and 5.62 (95% CI = 4.81 to 6.56) per 10 000 AOM episodes, respectively. The incidence of brain abscess and orbital cellulitis following AS was 0.11 (95% CI = 0.05 to 0.26) and 1.50 (95% CI = 1.17 to 1.90) per 10 000 AS episodes, respectively. Antibiotic prescription for AOM was associated with lower odds of developing acute mastoiditis (odds ratio [OR] 0.54; 95% CI = 0.37 to 0.79); NNT to prevent one case was 2181 (95% CI = 1196 to 5709). Antibiotic prescribing for AS was associated with lower odds of subsequent brain abscess (OR 0.12; 95% CI = 0.02 to 0.70); NNT to prevent one case was 19 988 (95% CI = 4951 to 167 099). No significant association between antibiotic prescription and development of orbital cellulitis following AS were found (OR 0.56; 95% CI = 0.27 to 1.12). Conclusion Serious complications following AOM and AS are rare. Antibiotics are associated with lower odds of developing complications, but the NNT are large.