The incidence of acute otitis media in New Zealand children under five years of age in the primary care setting

INTRODUCTION: Acute otitis media (AOM) is a common childhood infection. Baseline data are required to evaluate potential changes in the epidemiology of AOM with new public health measures. AIM: To estimate the incidence of AOM in children under five years of age in primary care in New Zealand. METHODS: Using a cohort study design, consultation notes from 1 November 2008 to 31 October 2009 from 63 primary care facilities were analysed for new and recurrent episodes of AOM, complications, antimicrobial use and outcome. RESULTS: There were 19 146 children in the sample. The raw incidence of AOM was 273 per 1000 children (27.3%; 95% CI 216-330). Of the 3885 children, 2888 (74%) had one episode of AOM and 152 (4%) of these children developed recurrent AOM. Incidence declined with age. There was no difference in incidence between Maori, Pacific and 'Other' ethnicities. Antibiotics were used to treat 2653 (51%) AOM episodes and 113 (4.3%) of these children re-presented within three days of antibiotic therapy for persistent symptoms. Tympanic membrane perforation was the only complication noted, observed in 62 (1%) episodes. DISCUSSION: These data indicate that AOM is an important and frequent childhood infection in New Zealand. The show a significant decline in the use of antibiotics to manage AOM in concordance with accepted best practice. The complication rate of AOM is likely under-represented. This study enables future research into the effectiveness of current and future immunisations and changing management practices in New Zealand.