Public health impact of various risk factors for acute otitis media in northern Finland.

The aim of this study was to assess the excess risk attributable to alterable risk factors for acute otitis media in Finnish children, including day care attendance, parental smoking, and a short duration of breastfeeding. Data on a population-based cohort of 2,512 children were gathered from medical records and questionnaires from 1985 to 1988. Excess (attributable) fractions for the risk factors were calculated among 825 children (target population) followed for 2 years, from a dynamic logistic model fitted to the entire cohort (estimation data). In theory, one child out of every five affected in the exposed population would have escaped otitis media completely if he/she had been moved from nursery day care to home care, and two out of every five affected could have escaped recurrent episodes in this way. The corresponding figures for family day care were lower: one and two children out of every six affected, respectively. Cessation of parental smoking and breastfeeding would have smaller effects. The impacts were more modest in the whole population. Nevertheless, approximately 14% of all of the otitis media episodes would have been avoided if all of the children had been cared for at home. These figures are hypothetical, since it is unlikely that use of day care outside the home can be avoided altogether, but they offer further evidence of the notable role of day care attendance as a risk factor for otitis media.