Risk factors for recurrent acute otitis media and respiratory infection in infancy.

Using a cohort-based design and random enrollment, the relation of various risk factors to acute otitis media, respiratory infection and wheezy bronchitis was studied in 2512 children from the fetal period to the age of two years. The complex interrelations of the risk factors with each other were separated out by multivariate analysis, and the confounding effects of antenatal parameters were also standardized. Acute otitis media with effusion (AOME), as demonstrated by myringotomy, was analyzed as a specific subgroup of acute otitis media (AOM). Day care in local authority nursery was the major risk factor for both types of acute otitis media. The odds ratio (OR) for such children becoming 'otitis-prone' (greater than or equal to 3 episodes of AOME) was 1.8 (95% confidence interval, 1.4-2.2). Short duration of breastfeeding involved another significant risk of recurrent respiratory infections and otitis media, the OR for AOME being 1.5 (1.1-2.0) and that for recurrent respiratory infection 1.3 (1.1-1.6). Allergy and family day care were also significantly associated with infective parameters, but to a lesser extent. The risk factors for wheezy bronchitis were the same as for infections, indicating that wheezy bronchitis is closely related to infections.